Is there any research or data on which colors on book covers sell the most books (physical and ebooks)? I ask this because I have read some interesting articles about reoccurring themes in movie posters, one of which being the repeated use of orange and blue in the posters. There is just something about the use of those two colors in movie posters that just catches the eye. Is it the same for book covers? Just curious really, would like to see some data and maybe employ this in my own publishing strategy.