This is probably my second-favorite book, only surpassed by Bob Flexner's work.

It is a bit different in format than Flexner, so it makes a good complement to it.

 

Rather than just getting into the technology, it explores different techniques in coloring and finishing.  Each small topic is a few pages long and amply, as the name implies, illustrated.   If you are looking for how to do some particular type of thing, there's probably a topic on it in here.