The following example functions demonstrate how to extract individual red, green, or blue color component values from an RGB-formatted color value.
' ---------------------------------------------------------------------------
' Function: GetRValue
' Purpose: Returns the Red value from an RGB color value
' Arguments: vbLong - An RGB color value
' Returns: vbLong - A Red color value, -1 on error
' ---------------------------------------------------------------------------
Public Function GetRValue (val)
If val > -1 And val < 16777216 Then
GetRValue = val \ 256 ^ 0 And 255
Else
GetRValue = -1
End If
End Function
' ---------------------------------------------------------------------------
' Function: GetGValue
' Purpose: Returns the Green value from an RGB color value
' Arguments: vbLong - an RGB color value
' Returns: vbLong - a Green color value, -1 on error
' ---------------------------------------------------------------------------
Public Function GetGValue (val)
If val > -1 And val < 16777216 Then
GetGValue = val \ 256 ^ 1 And 255
Else
GetGValue = -1
End If
End Function
' ---------------------------------------------------------------------------
' Function: GetBValue
' Purpose: Returns the Blue value from an RGB color value
' Arguments: vbLong - an RGB color value
' Returns: vbLong - a Blue color value, -1 on error
' ---------------------------------------------------------------------------
Public Function GetBValue (val)
If val > -1 And val < 16777216 Then
GetBValue = val \ 256 ^ 2 And 255
Else
GetBValue = -1
End If
End Function