And why is this a problem?
I want to see if I hire mercenaries if they are in my team or my ally’s team or even my enemy’s team based on the colour on them.
Same goes for the Taverns heroes.
Why wouldnt you want to see the mercenary unit coloured as your player’ colour?? 
Its not about whether or not you are able to see it or not, what the issue is that especially with different dragon (and Frost Wyrms) models, the the wings for example are ENTIRELY colored with your team’s color…its just doesnt look good that way in my (and DeathKnight’s) opinion
I mean take a look at the comparison vids:
Imho the way the team colors were prestented in the original was much better as these red (or whatever your team color is) “patches” on the back and sides of the dragons. Now they have moved the team colors entirely on the wings, which imho is not the best solution.
I mean in most of the creeps, the team colors already look fine, but its mainly the dragons and frost wyrms that would need fixing. I mean the way Nether dragons have their wings only parially team colored doesnt look too bad at all.
I don’t get it. The whole game is literally gray washed. Theres 0 color anywhere.
i add some images to explain what wrong with team color on dragon wings