Look at this “Split Testing” Noah Kagan did to find the right book cover: He took a picture from a book store shelf, then rendered different colors of the book to see which stood out the most. The yellow book blended in, but the green stood out! He also ran Facebook Ads to test which book covers/colors people would click on the most: The end result looking like this! You can also watch Noah talk about how he reverse-engineered reaching NYTimes Bestseller with his book launch here: https://youtu.be/GeIk19HzZSc