Yellow is the first colour potted in the colours-only stage of a snooker frame.
During the opening part of a frame, players alternate reds with nominated colours. Each red remains off the table after it is legally potted, while a colour is normally replaced on its spot. After the final red has been removed, the colours are played in a fixed order rather than being nominated freely.
That order is yellow, green, brown, blue, pink and black. The yellow is therefore the first colour required after the reds have disappeared. Its value is two points, the lowest of the six colours. The green is worth three, brown four, blue five, pink six and black seven.
The yellow is positioned on the baulk line, at one end of the D, with the green and brown completing the three baulk-line spots. Players sometimes confuse the yellow’s first place in the colours sequence with its position on the table, but the sequence is determined by scoring value, from two through seven.