New Post: Index color and RGB color

I was working on an app which replace rgb values in a pcx using the below code

using (MagickImage image = new MagickImage(@"E:\Development\DOTNET\PCXEditor\RGBEditor\18975253ee.pcx")) { MagickColor target = new MagickColor(128, 118, 118);
MagickColor fill = new MagickColor(100, 105, 110);

image.Opaque(target, fill);

image.Write(@"E:\Development\DOTNET\PCXEditor\RGBEditor\1897525311-changed.pcx"); } The problem i was facing is the output PCX file is in RGB mode , I need this to be in INDEX color mode Any help is greatly Appreciated