I try too with a hexa editor but.....nothing.

Why should be so hard to change an ordinary text / colour when are so many ways to change advanced dll's ?

Windows generally stores colours as BGR, so try AA0000.

Why does it store them like that?

Eh, don't ask me. That's just how x86 CPUs generally handle things.

You guys are talking about the part where you read the license, make partitions, etc? That appears to be some sort of text-based environment. It probably doesn't use any bitmaps; may even just be the 16 colours you get in older programs like QBasic.