Python 15, Choose wisely when selecting pastels, the chances of getting one that will not darken up are against you. I like the nerd lemons, but again you will need to look at alot of them to get a good one. there are also other bloodlines that if you look real hard, you will be able to select a brite one that will retain the yellow well. dont be in a hurry to buy something, take your time and you may end up with a jewell like I did.