I've recently installed my U310BT in my 07 Rabbit and found the preset colors for illumination, but I can't seem to find how you install custom colors to an SD card. Does anyone know how to do this?

Use the AVIC Feeds program on your computer, it's under Settings Replicator

(I used photoshop to choose the color I wanted to match my illumination of my car's dash,

Then I took the RGB values out of photoshop and inputted them into the Settings Replicator)

After that, save it to an SD card and put it into the head unit.

Awesome! This is exactly what I was looking for. Last question and its a long shot. Does anyone know the RGB combo for the blue in an 07 VW Rabbit?

All I did was take a picture of my dash at night to capture the illumination color, then load the picture in photoshop and use the eye dropper to find the RGB values. It was close enough