A roulette wheel typically contains slots with numbers 1-36 and slots marked 0 and 00. A ball is spun on the wheel and come to rest in one of the 38 slots.
Eighteen numbers are colored red and 18 numbers are colored black.
The 0 and 00 are colored green.
If you bet on particular number, The house pays off odds of 35 to 1. If you bet on a red number or black number and win the house pays 1 to 1 (even money ).