How to use individual textures as font in GUI?

I can't phrase it too well in the question title, but what I basically want is to use hand-drawn textures as characters rather than a font file for font in my GUI. At least from what I can tell, font text can only be one color, and honestly this looks dull in a game. What I want to use is my own font in which I draw out each character, save each one as an individual texture and then use those textures as 'font' with GUIText, if that makes any sense.

I have, once before, wrote a script that takes in a string, reads it character by character and displays the texture relevant to each letter (so it basically worked like a font). Only problem is was that it wasn't for GUI, which is what I want to use it in now. Any way to do this? Or simply apply the same method but use GUITextures instead?