This is really similar to the Warmth Preserver but with different colors and undershirt

As others have said, the paint area could use some adjustment or downsizing. Personally, I think it's alright by most standards compared to other cosmetics (especially for the Heavy) but some adjustments (such as making the collar unpaintable and team colored) would help.

Heavy tourism but awesome and has oversized paint areas
Maybe make it like theres only a "stripe" that is paintable, and is slightly darker teamcolor when no paint is applied

Not a bad cosmetic but the paintable area is a bit large. I also personally find it strange to give said area team variations by default but then let that area be painted over (although I'm sure there's examples of other cosmetics doing the same thing).
Otherwise it's an arguably better Warmth Preserver mixed with a neat shirt.

Is it just me or is the paint region huge?

heavy tourism but awesome