A/C cover???

As stated, my guess is it is the flavor of the day/year.

Black colour absorb heat from sun ray . White deflect part of the sun ray and stay cooler. But here something , vent cover are not really white but kind of translucent letting heat ray get inside . Black block this.
For AC , I do not believe this will make any difference . And yes, black is better at UV IF they put enough carbon black and I have strong suspicion they don't . Also with black plastic part , you can use more recycle products and the customer will not know.
PS I work in the plastic raw material all my life.

My guess it that white would be preferred. Central air units for homes want to be placed on a shady side of a home. Black gets hotter than white in the sun. I think it's just the trend, and not thought out very well.

Brian

The evap cooler is under another insulated cover so that back shroud should have NO affect on the cooling ability of the RV A/C Unit.

A dirty evap cooler, dirty condenser cooler and dirty air filter WILL

The compressor generates more heat than the black cover in full sun. I'm betting the air space under the cover actually cools down when it shuts off.

It definetly is worse for efficency. If you are borderline with enough cooling power, it will result in a warmer interior, though probably not huge difference.

This is purely form over function. Black covers look nicer. When it first started, it was mostly high end MH's and 5er's where they run on 50amp power and have two A/C units, so they could easily over power the extra heat load. Now, I am seeing them on smaller lower end units.

I'd be more worried about the dark paint job on the walls. The A/C cover represents probably less than 5% of the surface area exposed to the sun.

Black holds up better from suns U V rays.Ever notice how all the sailboats in a marina have blue covers on the sails when not in use.There is nothing that prevents you from painting the a\c cover to match your rig.

Black is the flavor of the day. Most new models also have black power outlets inside. Sort of like how fridges were all once avocado green or harvest gold or brown.

Matching body paint colors.....

A/C works through heat exchange. More heat won't be a problem.

Interesting thought. I have black vent covers and all I know is that it does keep my coach cooler than the the white ones.

That said I think the main reason is to match the full body paint RV's.