It's really personal preference. Color is the only difference.
Some people prefer brown for Leos because it fits the desert theme and green for tropical species because it's more jungle themed.
I dont really care for reptile carpet myself cause if you feed them on the carpet and they bite the carpet by mistake their teeth get caught in the carpet.
It's all personal preference and if you want a real desert look they have some that have rocky feel to them and look like sand but have no loose pieces that can cause impaction. I've seen them at pet. Co and a few other small time petshops in my area, I think zoo med makes them but I'm not 100% sure