There are a total of 26 slots on a roulette wheel, numbered 1 through 26. When someone bets on a particular number, they are actually betting on the color of that number.
So if someone bets on the number 3, they are betting on the color red.
There are basically four colors that appear on a roulette wheel more than any other: black, red, green, and yellow. So if someone bets on 3, they are essentially betting on the color red.
However, there is one other color that appears quite often: black. So in reality, it’s not always clear which color somebody is betting on.
