The skin tone one gets from sitting in a basement playing call of duty for days without sunlight.
Jeff: Dude, you have such a great Xbox Tan.
Jim: I know right!, i haven't gone outside all week!
Jeff:... I don't think we should be friends.
A really, really, really, really pasty white skin tone. When someone gets an xbox they invariably spend too much time indoors playing it, and the lack of sunlight they recieve results in a lack of melanin in the skin, turning them albino white.
Hilariously, this insult should be applied to people who through no fault of their own cannot develop a dark tan, such as the elderly, ginger-haired folk and computer nerds who should know better.
Max: "Hey, look at that pasty white guy"
Bubba: "Yep, he's sporting a real xbox tan"