This is a very cute tool that takes a source code and adds color tags. The program was made by PrBacterio on www.coderforums.net . The application is written in O'Caml.
let rec sum_int_list = function
 -> 0
| h::t -> h + (sum_int_list t);;
Only thing, it was designed for VBulletin, so with YaBB you can't use the code tag if you want to color you code.