This is spring or summer edition (there are total 4 of them for each season). This change mitght be intentional, but I may be wrong

I haven't looked at the variants yet, but does this mean only the white variant will be best now?

Or are there multiple tiers of each color?

Camo color isn't chosen by the temperature, but for the environment you're trying to blend into.

This also would be a great example for why we need layered clothes.
Add slots to the jacket to add layers of warmth

Hunter's wear longjohns under their hunting clothes to add extra warmth

These values seem to be a bit arbitrary? For instance the summer jacket (heatIsolation=0.30000001;) has less insulation than a hoodie (heatIsolation=0.60000002;).

It might seem counterintuitive for a “primitive” hunting jacket to have low insulation, especially when players rely on protective gear to stay warm in DayZ’s harsh environments. But I appreciated the block blast when I played around with it.

Gee guys, just calm down a bit. There are 4 variants, with different insulation. If you don't like white one use brown from Chernarus for better insulation. On Sakhal you easily can survive even with summer/sping variant - 'cause of the heat buff. And I like to play Livonia most of the time, but even now 50% of times I get yellow temperature in summer variant, which leads to loosing water faster. Imagime they boost spring/summer insulation - I will be getting constant red in worst case, or yellow all the time. So yea, you need to see both sides of the coin