Running rigging in colors?
I''ve always found it a good idea, particularly with multiple halyards. Less important with sheets, although traditionally our spin sheets and guys are different colors. (With occasional newbies on the boat, it''s sometimes easier to tell them to grab the blue line than to tell them to haul in on the cunningham.)
One word of caution, red tends to fade very quickly with UV. Turns a lovely shade of pink in less than a season. An alternative is to go with white lines with different color flecks.