Why is partial colour up not allowed?

[Julio88]

Partial colour up is not allowed in roulette because it would give the players an advantage. Partial colour up means that players could bet on different combinations of numbers and colours and would be able to receive a payout for each combination. This would increase their chances of winning and give them an unfair advantage over the house. For this reason, casinos typically do not allow partial colour up in roulette.