[brian] tipped me to this excellent colormeter project for calibrating your home theater/HD/etc It was designed specifically for the HCFR Colormeter software project. The project page is in english, but the probe writeup is in french. The fish well help you understand it while you resist the taunts avoid the flying cows. The device has at least one color sensor (a second is optional as well as an IR led or two for computer hardware controls) and connects to your computer via USB. The brain is a PIC 18F2550 (the fish calls it a PEAK) – no in circuit programming, you’ll need a programmer to build it.