The IDLgrPalette::GetRGB function method returns the RGB values contained in the palette at the given index. The returned value is a three-element vector of the form [red, green, blue].
Result = Obj->[IDLgrPalette::]GetRGB(Index)
Returns the RGB values contained in the palette at the given index.
The index whose RGB values are desired. This value should be in the range of 0 £ Index < N_COLORS, where N_COLORS is the number of elements in the color palette, as returned by the N_COLORS keyword to the IDLgrPalette:GetProperty method.