Yeah, yours looks good too. The bad thing about the Spark Fun light sensor is there is not that much information on the website about it. I might hold of on the light sensor idea because it is very complicated and I have some other orders in the mail.
The Sparkfun sensor has an I2C interface (aka TWI, or Two-Wire Interface). It is possible to program a VEX Microcontroller to talk to I2C devices, but it is not easy.
Also, it is a 3.3V (max) part, so you’ll have to add a voltage regulator, and possibly line drivers/receivers to ensure all he signals are in-spec.
The data sheet for the sensor chip can be downloaded at the bottom of this page.
If you want a low-tech solution, you could just use three VEX light sensors with red, green, and blue filters. Or you could use a single light sensor and use a servo to rotate a color-wheel over it. Point a bright white light, such as the VEXplorer flashlight, at the point you want to read, and make sure all the light sensors are aimed at that spot.
Electrically, you should be able to hook it up, but I don’t think it’d work very well. The problem is that it requires you to count pulses over a 50ms period, but the ~17ms periodic service routine that run in the Vex microcontroller is likely to interfere with this. The result would be some lost counts, though I don’t know how many.
You might be able to configure one of the timers into counter mode to count pulses, but I’ve not gone that far into PIC details yet to know how workable that is off the top of my head.