HBU – Enhanced human units with a blue color scheme.

So, I had an idea that it would be interesting to recolor the standard Knight hero model (and, if there's time, the campaign heroes) by changing almost all the red colors (cloak, some parts of the saddle) to blue (it would be interesting to watch a battle between blue heroes and red ones). It just seems a bit strange to see a hero in a red cloak commanding a blue army (this is just my personal opinion, so you can simply dismiss my idea).