Capture And Display RGB Value Of Cell Interior

I'm trying to write a routine that will display the Red, Green and Blue RGB properties of a cell's interior colour.

I found the following function:

Code:

Function SingleColorFromRGB(colorWanted As String, RGBValue As Long) As Long
Dim rColor As Long, gColor As Long, bColor As Long
If RGBValue < 0 Then GoTo ReturnError
rColor = RGBValue Mod 256
RGBValue = Int(RGBValue / 256)
gColor = RGBValue Mod 256

[Code]...

How I should call this function in a worksheet, or failing that, come up with something better e.g. a message box that will display the numeric values of each RGB property for the selected cell, or a single cell worksheet name?