My mom does all white lights, on the tree, on the house, and most of her outdoor decorations are white lights with a few colored accents thrown in.
Our Christmas tree is the only lights we have, and its a pre-lit all-white-bulb tree. I just think it looks prettier, but still enjoy looking at all types of lights and colors
I theme and mix the clours - this year I have red and silver/white in the living room and on that (catproof) tree and green/gold/yellow on the main tree in the dining hall. I have to say I hate the blue ones - to me it is not a Christmas colour.
Colored lights. I do not like all white lights. However, when doing colored lights when I used to decorate, I did not put up strings of mixed colored lights. Because from a distance, they blend together to make white or almost white. What I would do, is put up strings of all one color. For instance. One tree all green, another all blue, trim of the house all red, etc. I also used colored spot lights. I did use some white lights a few times in a couple trees, but would enhance the same tree with a colored spot light.