How to tame overly bright mix?

Who remastered it? And what were they using as a reference point? Come to that, what are you using as a reference point?

I used to get this quite a lot - people saying that what they'd got wasn't 'right'. What I found generally was that if the remastering had been done professionally, it was fine, and what was really needed was a little correction to their listening conditions. But for any other sort of remastering, all bets were off. So I'm not saying anything about your situation here - just trying to establish the background. Audition has some tools that can help you decide what to do, but yes - generally it's going to be an EQ-based solution, but there are other options too. For instance, it's possible to add a little low end warmth using an exciter (unfortunately not the one in Audition, which is broad spectrum) and that can alter your perception of a mix without altering the overall response at all.

How do you decide what to do? I suppose I have a slight advantage over most people - an acoustically treated edit suite with a pair of Neumann KH420s, and that makes decisions and comparisons a lot easier to make because it's stunningly revealing. But in general, you make immediate comparisons between tracks that you know sound good and the one you're concerned about. Audition's good for this - just put all the tracks into Multitrack and use the Solo button to hop between them. You need the Solo mode (Edit>Preferences>Multitrack>Track Solo) set to Exclusive to do this. After a while, it becomes relatively easy to work out what it really is that you don't like - and it isn't always what you think at first. Then you can decide more sensibly what it is you're going to do about it. It's worth spending a little time on this, because you have to live with the results.