A roulette wheel has 36 spots, numbered 1-36. The numbers 1-18 are black, 19-36 are red, and 37 is green.
The layout of the wheel can be a major factor in determining which colors will be on the table at any given time. .
The wheel is spun by a croupier and after it has completed one revolution it is stopped by the lever that pushes against the rim of the wheel. The number that is shown on the indicator (or “face”) of the wheel at that instant corresponds to the number on the lever.
This means that if black was on the lever when the wheel stopped, black will be shown on the indicator as it turns around. If red was on the lever, then when it shows green on the indicator, red will be shown on the table as it turns around.
If there are any other numbers showing (such as yellow or green), then those particular colors will not show until another number (higher or lower) has been shown on the indicator and then those colors will move up or down to take their place on either side of that number.
