Loosening Up With Color

I know, I know, he should be doing Downward Dog instead of the Cobra Pose. (Click on the image for a larger view.) This is from an early reader chapter book I've been working on.  I'm really trying to concentrate on making my color palette more harmonious, which is something I struggle with. But I've found a book that's been super helpful.  It's an oldie but goodie called "Making Color Sing," by Jeanne Dobie.  One of my buddies over at PBAA recommended it, so I bought an old copy on Amazon.  (Word has it that the newer edition has lousy color reproduction, go figure, so if you buy a copy, make it the 1986 edition.)  The main lesson so far is to limit the number of colors you use and create your palette by mixing. So for this illustration the only watercolors I used are Rose Madder Genuine, Aureolin Yellow, Cobalt Blue, and Viridian Green.  I think these guidelines really help. What do you think? Do you limit your palette?