This aspect seems to have been dropped once TNG hit the airwaves...
{I just wanted to use one of the new smilies or 'graemlins').... 
Anywho, in TOS, it looks like the Commodore's wear either red or yellow--Mendez, Stone, Stocker...{and could have worn blue}. However, I don't recall seeing any Captain's wearing anything other than gold....although, there probably were a few who did, offscreen.
Did commanders have prerogative? {Well, in TNG they even had a 'Captain's Yacht'! Although, I don' think we ever saw Picard or any other captain use it..}


Anywho, in TOS, it looks like the Commodore's wear either red or yellow--Mendez, Stone, Stocker...{and could have worn blue}. However, I don't recall seeing any Captain's wearing anything other than gold....although, there probably were a few who did, offscreen.
Did commanders have prerogative? {Well, in TNG they even had a 'Captain's Yacht'! Although, I don' think we ever saw Picard or any other captain use it..}