Every video about growing citrus tells you that the ripeness is not based on color and ripeness is kind of just trial and error from what I have seen. To me at least no orange is as good as the Cara Cara orange for my tastes anyway. I have not tried a blood orange as I have not really seen them in stores so I have not tried all of them. The Cara Cara just has that super sweet taste with some tangyness which I like. Same reason I like mandarin. Mandarin have that super sweetness with that tang.