How remove/substitute purple color from game.

My request is simple: remove the purple color, replacing it with another color (white, or light gray for example).
I kindly ask you to be precise in the instructions, I don't have solid computer skills, so a step by step guide would be really useful.Tnx.

I feel pretty sure one of prod80's shaders (they're labelled starting with PD80) can do exactly this but I'm not sure which off the top of my head - you're looking for something along the lines of a selective emphasize/de-emphasize shader. I haven't used them myself, but I'd bet one of either PD80_04_Color_Isolation.fx or PD80_04_Selective_Color_v2.fx can do this job for you.