Hi

Yes, possible. You are limited to 56 colors, and what you color with is a
color number from 1 to 56. Those 56 can be customized for each single file.
This RGB thing is easiest achieved with macro code, like this demo altering
color 45:

Sub test()
ThisWorkbook.Colors(45) = RGB(234, 251, 178)
Selection.Interior.ColorIndex = 45
End Sub

HTH. Best wishes Harald

"Heather" skrev i melding
...
There is a very limited selection of colors for fill and text for that
matter. I'm looking to change the fill to a specific RGB color. Please
advise
if this is possible

Thanks!!!