scrounge: /skrounj/ informal verb: to actively seek [books] from any available source
I've already made a list about books geared toward art in general, but this one is specifically about colors. Of course, there are many many picture books that introduce colors to children, some based on particular themes that may be more exciting to some children than others. These are just some of our personal favorites out of the many fun and useful books out there.
Even though I grew up with Dr. Seuss books, it wasn't until I was an adult that I realized he had produced a "colors book" as well. However, My Many Colored Days does not contain his trademark Seussical illustrations -- instead, the manuscript of this poem was illustrated by Steve Johnson and Lou Fancher, and not published until after Seuss's death. What results is a vibrant celebration of color and emotion, as each color has a particular feeling paired with it -- from happy and energetic to low and upset, the colors help to visualize an animal embodying something about each emotion. But in the end, the book emphasizes that "I'm still me" through all of it.
From another well-known children's book author, The Artist Who Painted a Blue Horse is Eric Carle's tribute to German painter Franz Marc. While nothing is said of Marc in the text, there is a short informational paragraph about him at the end. Carle encountered Marc's work while growing up in Germany -- Marc was one of many "degenerate" artists whose work was banned by the Nazis, and one of his more famous paintings is of a blue horse. This book includes animals drawn in all the "wrong" colors -- a purple fox, an orange elephant, etc. It is a way of encouraging children to not let conventional expectations limit their art. For another colorful book of animals illustrated by Carle (mostly conventionally), see also Brown Bear Brown Bear What Do You See?. Also, while it's not a "colors book," Carle's Animals Animals pairs his vibrant illustrations with sayings and poems about many different animals (most conventionally depicted, this time).
While Green is not a regular colors book that depicts every major color, it also doesn't limit itself entirely to green either. Many shades are explored here -- from jungle green to "shaded" green (trees). Also, each page includes clever cut-outs that become very different things on each side of the page. Not only that, but the paintings are lovely, full of textured detail. See my full review here.
For those who are fans of L.M. Montgomery's Anne of Green Gables series, Anne's Colors is a beautiful celebration of major scenes from the first book, as a means of introducing colors. The illustrations were created with fabric and embroidery, which adds some texture and life to Anne's world. We get to see a brown dress (with puffed sleeves, of course), red cordial, blue sky, etc. See my full review here.
For children who enjoy monsters, Monsters Love Colors, by Mike Austin, is an exuberant (and of course colorful) celebration of colors and how fun it can be to color with them and mix them up. This book uses monsters to show how the primary colors can be mixed to create the secondary colors, and that when they're all together, they make a beautiful rainbow. For kids who don't like monsters (or just for a more subdued book with a similar premise), see Mouse Paint, which demonstrates the same mixing of colors.