Anyway, it's tiring sure, but it's also quite fun. matching all those lines, colors, and characters together in a scene. One of my favourite concept artist is Evgeni Tomov, who created Les Triplettes de Belleville with Sylvain Chomet. If you haven't watch it, I strongly recommend you to. The animation has no dialogue aside from the grunts, laughs, and other miscellaneous sound. The style is very interesting too.
Again background really intrigues me, Evgeni Tomov really has a way with lines. Here are some examples:
And the finished colored piece:
Pictures taken from http://livlily.blogspot.com/2011/02/les-triplettes-de-belleville-triplets_01.html
If you want to see more go to Evgeni Tomov website or the link above.