<span> It means a phrase or opinion that is overused and betrays a lack of original thought.</span>
Well, since jaunt and excursion mean relatively the same things, they are near synonyms, we are looking here for a word that has a relatively similar meaning to that of 'resignation'. Since you didn't give us any examples, I will just list you some of its synonyms: departure, retirement, termination, abdication, leaving, notice, abandonment, withdrawal, etc.
'Horse of another color' is the opposite expression from Shakespeare's 'a horse of that color' in the Twelfth Night Act 2 Scene 3 where Maria told Sir Toby Belch that her purpose was indeed a horse of that color which meant that Sir Toby Belch got the same idea as hers. So, 'horse of another color' is an idea different from the other.