Is Color by Number part of Coloring Books?

No. Color by Number is a studio of its own ($97, paid once). It uses the same drawing engine and adds numbers in the spaces, named color keys, mystery mosaics, color by letter, word, sum or shape for children, photos made into paint by number, your own pencil sets and answer keys. In a Coloring Books book, the "Color by number" card explains this. If you also own Color by Number, the card offers "Make this a color by number book" (see THE COLOR BY NUMBER CARD).