Color fonts may cause issues in production and some older systems as well as some applications can't handle them. My font Geometric doesn't work without color, so I designed a black and white version and substituted the color with hatching. Picking up Art Déco elements as well as a bit of 70ies design.
Please read about the process in an article/tutorial I have written for the Fontself weblog: How to design a color font with Illustrator & Fontself (in one afternoon)
