How do you score in snooker?

By scoring 1 point for a red followed by potting a colour. Then another red followed by a colour & so on. Colours score 2 for Yellow 3 for green 4 for brown 5 for blue 6 for pink & 7 for black.
The related link gives you more information. In summary if a red is potted it is a score of 1. This may be followed by any color where yellow is 2, green is 3, brown is 4, blue is 5, pink is 6 and black is 7. Once all the reds have been potted it is the colors again in sequence. Points are also awarded when an opponent fouls. The minimum foul score is 4 points but a foul on the blue, pink and black is 5, 6 or 7.