Homebrew PCBs

You can toner transfer any color you want onto the board *after* you
etch it to make a silkscreen layer :-)

But I find that a color laser (I have an HP 2550N) is really handy -
color coded schematics and board layouts, colored maps from google,
etc.  You won't regret it.  For business use, spot colors (i.e. color
just one header, or a logo) can be very effective.