RGB Function

Returns a Long representing an RGB color value from red, green, and blue color components.

Syntax

RGB(red, green, blue)

Parameters

red - Required. Integer in the range 0-255 that represents the red component of the color.
green - Required. Integer in the range 0-255 that represents the green component of the color.
blue - Required. Integer in the range 0-255 that represents the blue component of the color.

Return Value

Returns a Long representing the RGB color value. The value is calculated as:

RGB = red + (green * 256) + (blue * 65536)

The return value is a Long integer in BGR (Blue-Green-Red) byte order, which is the standard format for Windows color values.

Remarks

The RGB function creates custom color values by combining red, green, and blue components. This is the primary way to specify colors programmatically in VB6 beyond the predefined color constants.

Each color component must be in the range 0-255: - 0 represents no intensity (color is off) - 255 represents maximum intensity (color is fully on) - Values outside this range are automatically adjusted to fit within 0-255

Important Notes: - The return value uses BGR byte order (not RGB order) for Windows compatibility - RGB(0, 0, 0) = Black (0x000000) - RGB(255, 255, 255) = White (0xFFFFFF) - RGB(255, 0, 0) = Red (0x0000FF in BGR format) - RGB(0, 255, 0) = Green (0x00FF00) - RGB(0, 0, 255) = Blue (0xFF0000 in BGR format) - Values greater than 255 are treated as 255 (saturated) - Negative values are treated as 0

Color Mixing: - RGB(255, 0, 0) = Pure Red - RGB(0, 255, 0) = Pure Green - RGB(0, 0, 255) = Pure Blue - RGB(255, 255, 0) = Yellow (Red + Green) - RGB(255, 0, 255) = Magenta (Red + Blue) - RGB(0, 255, 255) = Cyan (Green + Blue) - RGB(128, 128, 128) = Gray (equal components)

Typical Uses

Custom Colors: Create specific colors not available as constants
Dynamic Coloring: Calculate colors based on data values
Gradients: Create smooth color transitions
Color Schemes: Define coordinated color palettes
Data Visualization: Color-code data points, charts, or graphs
User Preferences: Allow users to select custom colors
Theme Systems: Implement application-wide color themes
Image Processing: Manipulate individual pixel colors

Basic Examples

Example 1: Primary Colors

' Set form background to pure red
Form1.BackColor = RGB(255, 0, 0)

' Set label to pure green
Label1.ForeColor = RGB(0, 255, 0)

' Set button to pure blue
Command1.BackColor = RGB(0, 0, 255)

Example 2: Custom Colors

' Create a nice orange color
Dim orange As Long
orange = RGB(255, 165, 0)

' Create a purple color
Dim purple As Long
purple = RGB(128, 0, 128)

' Create a brown color
Dim brown As Long
brown = RGB(165, 42, 42)

Example 3: Shades of Gray

' Create various shades of gray
Dim lightGray As Long
Dim mediumGray As Long
Dim darkGray As Long

lightGray = RGB(211, 211, 211)
mediumGray = RGB(128, 128, 128)
darkGray = RGB(64, 64, 64)

Example 4: Data-Driven Coloring

' Color-code values based on magnitude
Dim value As Double
Dim cellColor As Long

If value > 100 Then
cellColor = RGB(255, 0, 0)      ' Red for high values
ElseIf value > 50 Then
cellColor = RGB(255, 255, 0)    ' Yellow for medium values
Else
cellColor = RGB(0, 255, 0)      ' Green for low values
End If

Common Patterns

Pattern 1: `CreateGradient`

Function CreateGradient(startColor As Long, endColor As Long, _
steps As Integer, stepNum As Integer) As Long
' Create a color between startColor and endColor
Dim startR As Integer, startG As Integer, startB As Integer
Dim endR As Integer, endG As Integer, endB As Integer
Dim r As Integer, g As Integer, b As Integer
Dim ratio As Double

' Extract RGB components from start color
startR = startColor And &HFF
startG = (startColor \ 256) And &HFF
startB = (startColor \ 65536) And &HFF

' Extract RGB components from end color
endR = endColor And &HFF
endG = (endColor \ 256) And &HFF
endB = (endColor \ 65536) And &HFF

' Calculate interpolation ratio
ratio = stepNum / steps

' Interpolate each component
r = startR + ((endR - startR) * ratio)
g = startG + ((endG - startG) * ratio)
b = startB + ((endB - startB) * ratio)

CreateGradient = RGB(r, g, b)
End Function

Pattern 2: `ExtractColorComponents`

Sub ExtractRGB(color As Long, red As Integer, green As Integer, blue As Integer)
' Extract individual RGB components from a color value
red = color And &HFF
green = (color \ 256) And &HFF
blue = (color \ 65536) And &HFF
End Sub

Pattern 3: `LightenColor`

Function LightenColor(color As Long, percent As Double) As Long
' Lighten a color by a percentage (0-100)
Dim r As Integer, g As Integer, b As Integer

r = color And &HFF
g = (color \ 256) And &HFF
b = (color \ 65536) And &HFF

' Increase each component toward 255
r = r + ((255 - r) * percent / 100)
g = g + ((255 - g) * percent / 100)
b = b + ((255 - b) * percent / 100)

LightenColor = RGB(r, g, b)
End Function

Pattern 4: `DarkenColor`

Function DarkenColor(color As Long, percent As Double) As Long
' Darken a color by a percentage (0-100)
Dim r As Integer, g As Integer, b As Integer

r = color And &HFF
g = (color \ 256) And &HFF
b = (color \ 65536) And &HFF

' Decrease each component toward 0
r = r - (r * percent / 100)
g = g - (g * percent / 100)
b = b - (b * percent / 100)

DarkenColor = RGB(r, g, b)
End Function

Pattern 5: `BlendColors`

Function BlendColors(color1 As Long, color2 As Long, _
Optional ratio As Double = 0.5) As Long
' Blend two colors together (ratio 0.0 = color1, 1.0 = color2)
Dim r1 As Integer, g1 As Integer, b1 As Integer
Dim r2 As Integer, g2 As Integer, b2 As Integer
Dim r As Integer, g As Integer, b As Integer

' Extract components
r1 = color1 And &HFF
g1 = (color1 \ 256) And &HFF
b1 = (color1 \ 65536) And &HFF

r2 = color2 And &HFF
g2 = (color2 \ 256) And &HFF
b2 = (color2 \ 65536) And &HFF

' Blend
r = r1 + ((r2 - r1) * ratio)
g = g1 + ((g2 - g1) * ratio)
b = b1 + ((b2 - b1) * ratio)

BlendColors = RGB(r, g, b)
End Function

Pattern 6: `ColorFromHex`

Function ColorFromHex(hexColor As String) As Long
' Convert hex string like "#FF0000" to RGB color
Dim r As Integer, g As Integer, b As Integer

' Remove # if present
If Left(hexColor, 1) = "#" Then
hexColor = Mid(hexColor, 2)
End If

' Extract components (assumes format RRGGBB)
r = Val("&H" & Mid(hexColor, 1, 2))
g = Val("&H" & Mid(hexColor, 3, 2))
b = Val("&H" & Mid(hexColor, 5, 2))

ColorFromHex = RGB(r, g, b)
End Function

Pattern 7: `ColorToHex`

Function ColorToHex(color As Long) As String
' Convert RGB color to hex string
Dim r As Integer, g As Integer, b As Integer

r = color And &HFF
g = (color \ 256) And &HFF
b = (color \ 65536) And &HFF

ColorToHex = "#" & _
Right("0" & Hex(r), 2) & _
Right("0" & Hex(g), 2) & _
Right("0" & Hex(b), 2)
End Function

Pattern 8: `GetContrastColor`

Function GetContrastColor(bgColor As Long) As Long
' Return black or white for best contrast
Dim r As Integer, g As Integer, b As Integer
Dim luminance As Double

r = bgColor And &HFF
g = (bgColor \ 256) And &HFF
b = (bgColor \ 65536) And &HFF

' Calculate perceived luminance
luminance = (0.299 * r + 0.587 * g + 0.114 * b) / 255

If luminance > 0.5 Then
GetContrastColor = RGB(0, 0, 0)      ' Black
Else
GetContrastColor = RGB(255, 255, 255) ' White
End If
End Function

Pattern 9: `TemperatureToColor`

Function TemperatureToColor(temp As Double, minTemp As Double, _
maxTemp As Double) As Long
' Map temperature to color (blue = cold, red = hot)
Dim ratio As Double
Dim r As Integer, g As Integer, b As Integer

' Normalize temperature to 0-1 range
ratio = (temp - minTemp) / (maxTemp - minTemp)
If ratio < 0 Then ratio = 0
If ratio > 1 Then ratio = 1

If ratio < 0.5 Then
' Blue to cyan to green
r = 0
g = ratio * 2 * 255
b = 255 - (ratio * 2 * 255)
Else
' Green to yellow to red
r = (ratio - 0.5) * 2 * 255
g = 255 - ((ratio - 0.5) * 2 * 255)
b = 0
End If

TemperatureToColor = RGB(r, g, b)
End Function

Pattern 10: `InvertColor`

Function InvertColor(color As Long) As Long
' Invert a color (negative)
Dim r As Integer, g As Integer, b As Integer

r = color And &HFF
g = (color \ 256) And &HFF
b = (color \ 65536) And &HFF

InvertColor = RGB(255 - r, 255 - g, 255 - b)
End Function

Advanced Usage

Example 1: Color Palette Manager

' Comprehensive color palette management system
Class ColorPalette
Private m_colors() As Long
Private m_colorNames() As String
Private m_count As Integer

Public Sub Initialize()
m_count = 0
ReDim m_colors(0 To 99)
ReDim m_colorNames(0 To 99)
LoadDefaultColors
End Sub

Private Sub LoadDefaultColors()
AddColor "Red", RGB(255, 0, 0)
AddColor "Green", RGB(0, 255, 0)
AddColor "Blue", RGB(0, 0, 255)
AddColor "Yellow", RGB(255, 255, 0)
AddColor "Magenta", RGB(255, 0, 255)
AddColor "Cyan", RGB(0, 255, 255)
AddColor "White", RGB(255, 255, 255)
AddColor "Black", RGB(0, 0, 0)
AddColor "Gray", RGB(128, 128, 128)
AddColor "Orange", RGB(255, 165, 0)
AddColor "Purple", RGB(128, 0, 128)
AddColor "Brown", RGB(165, 42, 42)
End Sub

Public Sub AddColor(name As String, color As Long)
If m_count > UBound(m_colors) Then
ReDim Preserve m_colors(0 To UBound(m_colors) + 50)
ReDim Preserve m_colorNames(0 To UBound(m_colorNames) + 50)
End If

m_colorNames(m_count) = name
m_colors(m_count) = color
m_count = m_count + 1
End Sub

Public Function GetColor(name As String) As Long
Dim i As Integer

For i = 0 To m_count - 1
If UCase(m_colorNames(i)) = UCase(name) Then
GetColor = m_colors(i)
Exit Function
End If
Next i

GetColor = RGB(0, 0, 0)  ' Default to black
End Function

Public Function CreateGradientPalette(startColor As Long, endColor As Long, _
steps As Integer) As Long()
Dim palette() As Long
Dim i As Integer
Dim r1 As Integer, g1 As Integer, b1 As Integer
Dim r2 As Integer, g2 As Integer, b2 As Integer
Dim r As Integer, g As Integer, b As Integer
Dim ratio As Double

ReDim palette(0 To steps - 1)

' Extract components
r1 = startColor And &HFF
g1 = (startColor \ 256) And &HFF
b1 = (startColor \ 65536) And &HFF

r2 = endColor And &HFF
g2 = (endColor \ 256) And &HFF
b2 = (endColor \ 65536) And &HFF

For i = 0 To steps - 1
ratio = i / (steps - 1)

r = r1 + ((r2 - r1) * ratio)
g = g1 + ((g2 - g1) * ratio)
b = b1 + ((b2 - b1) * ratio)

palette(i) = RGB(r, g, b)
Next i

CreateGradientPalette = palette
End Function

Public Function GetColorCount() As Integer
GetColorCount = m_count
End Function

Public Function GetColorByIndex(index As Integer) As Long
If index >= 0 And index < m_count Then
GetColorByIndex = m_colors(index)
Else
GetColorByIndex = RGB(0, 0, 0)
End If
End Function

Public Function GetNameByIndex(index As Integer) As String
If index >= 0 And index < m_count Then
GetNameByIndex = m_colorNames(index)
Else
GetNameByIndex = ""
End If
End Function
End Class

Example 2: Heat Map Generator

' Generate heat map colors for data visualization
Module HeatMapColors
Public Function GetHeatMapColor(value As Double, minValue As Double, _
maxValue As Double) As Long
' Returns color from blue (cold) to red (hot)
Dim ratio As Double
Dim r As Integer, g As Integer, b As Integer

' Normalize value to 0-1 range
If maxValue = minValue Then
ratio = 0.5
Else
ratio = (value - minValue) / (maxValue - minValue)
End If

' Clamp ratio to 0-1
If ratio < 0 Then ratio = 0
If ratio > 1 Then ratio = 1

' Calculate color based on ratio
If ratio < 0.25 Then
' Blue to cyan
r = 0
g = ratio * 4 * 255
b = 255
ElseIf ratio < 0.5 Then
' Cyan to green
r = 0
g = 255
b = 255 - ((ratio - 0.25) * 4 * 255)
ElseIf ratio < 0.75 Then
' Green to yellow
r = (ratio - 0.5) * 4 * 255
g = 255
b = 0
Else
' Yellow to red
r = 255
g = 255 - ((ratio - 0.75) * 4 * 255)
b = 0
End If

GetHeatMapColor = RGB(r, g, b)
End Function

Public Sub ApplyHeatMapToRange(dataRange() As Double, controls() As Control)
Dim i As Integer
Dim minVal As Double, maxVal As Double

' Find min and max values
minVal = dataRange(LBound(dataRange))
maxVal = dataRange(LBound(dataRange))

For i = LBound(dataRange) To UBound(dataRange)
If dataRange(i) < minVal Then minVal = dataRange(i)
If dataRange(i) > maxVal Then maxVal = dataRange(i)
Next i

' Apply colors
For i = LBound(dataRange) To UBound(dataRange)
controls(i).BackColor = GetHeatMapColor(dataRange(i), minVal, maxVal)
controls(i).ForeColor = GetContrastColor(controls(i).BackColor)
Next i
End Sub

Private Function GetContrastColor(bgColor As Long) As Long
Dim r As Integer, g As Integer, b As Integer
Dim luminance As Double

r = bgColor And &HFF
g = (bgColor \ 256) And &HFF
b = (bgColor \ 65536) And &HFF

luminance = (0.299 * r + 0.587 * g + 0.114 * b) / 255

If luminance > 0.5 Then
GetContrastColor = RGB(0, 0, 0)
Else
GetContrastColor = RGB(255, 255, 255)
End If
End Function
End Module

Example 3: Theme Manager

' Application theme management with color schemes
Class ThemeManager
Private Type ColorScheme
Background As Long
Foreground As Long
Accent As Long
Highlight As Long
Border As Long
End Type

Private m_currentTheme As ColorScheme
Private m_themeName As String

Public Sub SetLightTheme()
m_themeName = "Light"
With m_currentTheme
.Background = RGB(255, 255, 255)    ' White
.Foreground = RGB(0, 0, 0)          ' Black
.Accent = RGB(0, 120, 215)          ' Blue
.Highlight = RGB(255, 255, 0)       ' Yellow
.Border = RGB(192, 192, 192)        ' Light Gray
End With
End Sub

Public Sub SetDarkTheme()
m_themeName = "Dark"
With m_currentTheme
.Background = RGB(32, 32, 32)       ' Dark Gray
.Foreground = RGB(255, 255, 255)    ' White
.Accent = RGB(0, 120, 215)          ' Blue
.Highlight = RGB(255, 200, 0)       ' Gold
.Border = RGB(64, 64, 64)           ' Medium Gray
End With
End Sub

Public Sub SetCustomTheme(bg As Long, fg As Long, accent As Long, _
highlight As Long, border As Long)
m_themeName = "Custom"
With m_currentTheme
.Background = bg
.Foreground = fg
.Accent = accent
.Highlight = highlight
.Border = border
End With
End Sub

Public Sub ApplyToForm(frm As Form)
Dim ctrl As Control

frm.BackColor = m_currentTheme.Background
frm.ForeColor = m_currentTheme.Foreground

For Each ctrl In frm.Controls
ApplyToControl ctrl
Next ctrl
End Sub

Private Sub ApplyToControl(ctrl As Control)
On Error Resume Next

' Apply based on control type
Select Case TypeName(ctrl)
Case "TextBox"
ctrl.BackColor = m_currentTheme.Background
ctrl.ForeColor = m_currentTheme.Foreground

Case "CommandButton"
ctrl.BackColor = m_currentTheme.Accent
ctrl.ForeColor = RGB(255, 255, 255)

Case "Label"
ctrl.BackColor = m_currentTheme.Background
ctrl.ForeColor = m_currentTheme.Foreground

Case "ListBox", "ComboBox"
ctrl.BackColor = m_currentTheme.Background
ctrl.ForeColor = m_currentTheme.Foreground
End Select

On Error GoTo 0
End Sub

Public Function GetBackgroundColor() As Long
GetBackgroundColor = m_currentTheme.Background
End Function

Public Function GetForegroundColor() As Long
GetForegroundColor = m_currentTheme.Foreground
End Function

Public Function GetAccentColor() As Long
GetAccentColor = m_currentTheme.Accent
End Function

Public Function GetThemeName() As String
GetThemeName = m_themeName
End Function
End Class

Example 4: Chart Color Generator

' Generate distinct colors for charts and graphs
Class ChartColorGenerator
Private m_baseHue As Integer
Private m_colorIndex As Integer

Public Sub Initialize(Optional startHue As Integer = 0)
m_baseHue = startHue
m_colorIndex = 0
End Sub

Public Function GetNextColor() As Long
Dim hue As Integer
Dim r As Integer, g As Integer, b As Integer

' Use golden angle for good color distribution
hue = (m_baseHue + (m_colorIndex * 137)) Mod 360
m_colorIndex = m_colorIndex + 1

GetNextColor = HSVToRGB(hue, 0.7, 0.9)
End Function

Private Function HSVToRGB(h As Double, s As Double, v As Double) As Long
' Convert HSV to RGB
Dim r As Double, g As Double, b As Double
Dim i As Integer
Dim f As Double, p As Double, q As Double, t As Double

If s = 0 Then
r = v: g = v: b = v
Else
h = h / 60
i = Int(h)
f = h - i
p = v * (1 - s)
q = v * (1 - s * f)
t = v * (1 - s * (1 - f))

Select Case i
Case 0: r = v: g = t: b = p
Case 1: r = q: g = v: b = p
Case 2: r = p: g = v: b = t
Case 3: r = p: g = q: b = v
Case 4: r = t: g = p: b = v
Case Else: r = v: g = p: b = q
End Select
End If

HSVToRGB = RGB(r * 255, g * 255, b * 255)
End Function

Public Sub Reset()
m_colorIndex = 0
End Sub

Public Function GetColorArray(count As Integer) As Long()
Dim colors() As Long
Dim i As Integer

ReDim colors(0 To count - 1)

Reset
For i = 0 To count - 1
colors(i) = GetNextColor()
Next i

GetColorArray = colors
End Function
End Class

Error Handling

The RGB function automatically handles out-of-range values:

Values greater than 255 are treated as 255 (saturated)
Negative values are treated as 0
Non-integer values are rounded to integers
No error is raised for out-of-range values

The function is very robust and rarely requires error handling:

' RGB automatically clamps values to valid range
Dim color As Long
color = RGB(300, -50, 150)  ' Treated as RGB(255, 0, 150)

Performance Considerations

The RGB function is extremely fast - it's a simple calculation
Can be called thousands of times with negligible performance impact
No need to cache RGB values unless doing complex color calculations
Extracting components from an RGB value is slightly slower than creating it

Best Practices

Use Named Constants: Define color constants for reusability
Document Color Choices: Comment why specific colors were chosen
Consider Accessibility: Ensure sufficient contrast for readability
Test on Different Displays: Colors may appear different on various monitors
Use Color Schemes: Create coordinated palettes rather than random colors
Extract Components Carefully: Remember BGR byte order when extracting
Validate User Input: When accepting color values from users
Use Gradients Wisely: Smooth gradients are more visually appealing
Consider Color Blindness: Test with color-blind-friendly palettes
Avoid Magic Numbers: Use RGB() rather than numeric color values

Function	Purpose	Returns	Use Case
RGB	Create custom color	Long (RGB value)	Precise color control, custom colors
`QBColor`	Get `QBasic` color	Long (RGB value)	Legacy compatibility, 16-color palette
vbRed, vbBlue, etc.	Predefined constants	Long (RGB value)	Quick standard colors
`LoadPicture`	Load image	Picture object	Complex graphics, images

Platform and Version Notes

Available in all versions of VB6 and VBA
Behavior consistent across all Windows platforms
Returns BGR byte order (standard for Windows)
Color values are compatible with Windows API functions
Maximum value is &HFFFFFF (16,777,215 colors)

Limitations

Limited to 24-bit color (16.7 million colors)
No alpha channel support (transparency)
Automatic clamping may mask input errors
BGR byte order can be confusing when extracting components
No built-in color space conversions (HSV, HSL, etc.)
No color validation or named color lookup

QBColor: Returns RGB value for QBasic color number (0-15)
Predefined color constants: vbBlack, vbRed, vbGreen, vbBlue, vbWhite, etc.
LoadPicture: Loads images with full color support
Point: Returns the RGB color of a specified point on a form or picture box