Red/amber lights in the rear of the vehicle, white lights, in front of it: that is the good old convention and certainly switching their places is a bad idea.

A quick search, however, shows other colors available to purchase. Concerning "to be seen" bicycle lights, should they be avoided?

More specifically, I would like to have one blue light in the front of my bicycle (just because I find it more pleasing), but am I asking for trouble if I replace my white light for the blue light? Would it be a better option to use both?