Wasp

What colors make Wasps more aggressive?

If you are perceived as a threat to them or their colony/nest site color isn't a factor in my experience. They could care less what you are wearing. As far as technical research data I don't have that answer for color reactions.

Just close proximity to a nest site with some species you are going to get nailed just because.

Skin color.

Whatever color approaches the hive...

I have found the paper wasps' to be the aggressive ones, especially the Orange ones, the dirt daubers, no problems, they are almost friendly.