When one colors, all negative emotions should wear off. Once you empty your brain and heart of those negative feelings that make you stressed out, there should be more room for positivity. Since you are positive and filled with good energy after coloring, there must be no difficulty in continuing your job with full productivity.
Instead of purchasing coloring books from art stores, simply use the internet to look for your child's favorite cartoon or any movie characters. You could try to look for categories, like Disney Characters, Princesses, Barbie or alphabets. The kind of coloring books that your child prefers. With such, there is an endless selection in which you could choose from.
You can choose from different characters: diligent Tecna or expressive Bloom and Musa, or maybe passionate Flora and Aisha. I'm sure here you can find a fairy especialy fo you and can find coloring page of your favorite farie. Especialy for you on pictures made colorfull previews of characters. It will be a hint for you in coloring process. But maybe you know better which colors shold be here. Go forward! Your fantasy is the best your guide. You can color pictures in any color of coloring pensils you have.