i like my white ones.. however, as the light penetrates into the ocean, it turns it a bluish tint.. so the blue ones would be more natural i guess. The white ones make it so that u can see the colors of your inhabitants better, IMO, as to where the blue ones color everything blue.. it is really just a personal preference. There is a similar thread on this exact topic, where we have posted pictures for all to see.. click here to see it!
I have the blue ones and like them. Alot happens when they come on. My cleaner shrimp goes crazy and starts to do a majority of his cleaning. His white lines look awsome under the blue light.