How may colored balls in billiards?

[15 reds, 1 yellow, 1 green, 1 brown, 1 blue, 1 pink and 1 black.]

Those are the colours used in Snooker which is played on an English Billiards table.

English Billiards uses just three balls: a red, a plain white and a 'spot' white (or increasingly commonly these days, a yellow).