I was going to say, I'm pro-bikini but used to live in Texas and wore longer sleeves to keep the sun off my skin because it kept me cooler doing that than if I wore a short sleeve shirt.
My understanding is that the fabric on burqas (or whatever those clothes are actually called) are extremely lightweight and provide shade, so they actually aren't any warmer than t-shirts and shorts. Possibly because they block the sun, they might even be cooler.
But that's simply what I have heard and I personally don't care to find out either way.
Or because they liked the colours for aesthetic reasons haha.
Also choosing a cloth colour has nothing to do with thermal mass and everything to do with absorbtivity/emissivity/reflectivity aka material properties affecting radiative heat transfer.
In any case, shirt colour has a small effect on temperature, maybe a 5°C (at most) difference between white and black, according to some studies. So unless you're really chasing the most optimal clothing, it's best to just wear what makes you happy.
The image above is a great example of the Virgin/Whore social complex. In each case, the woman is held to the demands of men. Women in robes are expected to appear perfectly chaste and insulated from the ravenous male gaze while women in bikinis are expected to be on display for the entertainment of those same men.
The shifting social expectations of a male-dominated social hierarchy decide which set of apparel is rewarded and which is shunned. In neither scenario is the woman genuinely considered free. She is simply subjected to a new set of burdensome social standards.
Sun tan lotion doesn't cut it for me, and I can go from white to red in a matter of minutes. So yeah, loose flowing clothes seem nice (not a fan of burqas esthetically but I never tried one so maybe they're comfy?)