That's the Edinburgh '86 tartan, also known as the Commonwealth Games 1986 tartan.

From the STA notes:
Designed by Ramsay Johnstone of Edinburgh Woollen Mill.
STS notes read as follows: "Designed by Ramsay Johnstone of Edinburgh Woollen Mill. worn as the official parade uniform by 230 athletes and the officials. The colours depict the blue of the Scottish flag, the white the running lanes on the track, and red the finishing tape at the end of each race. Still a popular fashion tartan in 1994.