Quote Originally Posted by Cana-Balsitic
The diffrent colors can distract other motorists and may even temporarily blind them. And since you only use the lights at night which is the worst time for windshield glare, you may inadvertantly cause an accident.

I see a lot of people driving around with thoes licence plate lights nowdays. Thoes are also supposedly illegal.
Another reason they are illegal is often also becasue there are specific colors associated with law enforcement and fire/rescue. In NY you can't have a blue light unless you're a cop or and EMT...