The Colors shield can directly plug on the Arduino board, and hook up with the RGB LED matrix, you can use the Arduino to drive the matrix like the Colorduino/Rainbowduino. The code of Colors shield is the same as Colorduino.
The Colors shield can be plug into the Arduino UNO/Duemilanove, so the controller is based on ATMega 168P/328P, the same as Rainbowduino. This design is to make user easily modify or write the firmware of Colorduino by Arduino IDE. But in order to better drive the RGB matrix and reach their best performance, we use the professional LED driver chip, and this chip comprises shift registers, data latches, 8×3 channel constant current and 64 x 256 gray level PWM for per color! Each channel provide a maximum current of 60 mA.
Each RGB dot has 160K colors in theory, and it’s easy to use the 6bit correction register to calibrate the current error for each color LEDs – we don’t think that Rainbowduino use an adjustable resistors to calibrate the current error is a good idea, because just 1 lap the resistor change from 0R to1K , you cannot get the exact value you need, but now, you have a 6bit software value to correct it.
Please visit Itead's wiki page for more info about this product.