There is no "standard" main/jib sheet color. For a long time (until recently), Hobie Cat used a red, fuzzy line for the main and a blue one for the jib. I think they were Sampson or Yale brand line (Matt M. can say for sure).

If you're choosing between the Swiftcord and the Sta-set, I'd go with the Swiftcord. Your hands will thank you. Sta-set has a hard finish and is stiffer. Swiftcord is soft and will run through blocks without hockling (twisting up).