Have there always been only 6 color balls in snooker?

Answer 1

The problem with answering this question is that the transition from Billiard to Snooker is a gradual one - so whilst games existed with less than six balls it is unclear whether we can call this snooker.

In its earliest form Snooker was a combination of two Pool type games - Life Pool and Pyramid Pool. The red balls come from pyramid pool, and the first colour, the black ball, from life pool. Three other colours were added a little later, the set being completed with the introduction of the brown and blue. The inclusion of these initial colours was first proposed in 1875 - dates for the inclusion of the brown and blue are unknown. It is unclear how well received or widespread these initial alterations were, but by 1882 the rules were standardised for a new game known as Snooker, with all six coloured balls included.

One notable exception to the regular 6 coloured balls is Snooker Plus, a variation of the six-ball game invented by World Championship winner Joe Davis. The game introduced an orange ball (worth eight points) and a purple ball (worth ten points), to make a total of eight coloured balls, in an attempt to reinvigorate the game. However, the concept didn't catch on and Snooker Plus is now widely obsolete