I'd say keep him as is. But go for a more natural colour if you have your doubts.
I'm not so sure about having enemies fight you dungeon style though (popping out of thin air). I'd say stick with how you did the rats and give people the option to fight them, or make them aggressively chase you if you get too close.
Even as early as the rat mission, that special reward could be for clearing a 'nest' of rats out and then just making that fight be with a few smaller rats and one big rat (Momma Rat if you will). Having to fight more rats is just adding time and not really difficulty. Plus, you can balance the fight at a later date.
Really interested in the classes to come, but for sure make it clear what each specialises in. Or just have the 'class representatives' come into the tent and allow the player to talk to them to get an idea.
Really liking the additions to the intro as well. Maybe even have the soldiers run away if the captain goes down.
Awesome stuff though, keep it coming!