That's not it. Indigenous people who live in desert regions have been wearing black for thousands of years, for good reason. Obviously, otherwise they'd stop. It's not just the fact that it's black... There's other things involved too, which help make things cooler. But it's not like somebody just made this up yesterday. Do a search and look it up.
White colour in desert areas are popular as if not more than black clothes is. check any pics from saudi or any other mid east north africa country, and you see that. Also they would not stop even if it would not be benefical as there is many cultural things that are being done and are just harmful to people and doesnt benefit anything. Culture wins over logic.
Sun radiates about 1000 watts of energy per square meter in equator . Human body produces about of 100 watts of useless heat? That is +900 potential, but how much black clothes absorb from it compared to white clotes, i dont know.
The article that claimed black clothes to be more cooler than white clothes is too small study and it isnt enough controlled study. Too many variables that can alter those results. But i understand logic behind that, but it would be great to see more controlled study about it. Clothes or fabric would need to be made by industrial quality and test would have to be in laboratory conditions where moisture, temperature, heat source and wind conditions could be controlled completely and accurately.
So i would wear white clothes in mojave as they are more popular in mid east anyways.
Then i would start to find all kinds of stuff from ruins and from abandoned houses. Then i would create small base to myself to some oasis or some near water source anyways and would build walls from rocks and i would put cars in only way entrance. If deathclaws would try to attack and destroy me, then i would shoot the cars and they would explode and kill every deathclaws that tries to come at me. Then i would eat them and sell their furs at local market. Then i would buy some wire cutters and additional ammunation and at night i would infiltrate helios station and steal few solar panels from there and install them at my base so i could play solitaire at my hidded base.Then i would go search for small water pump from the wastes and use the electricity to pump water from my oasis or fresh water source whatever it is, and then i would make few journeys to find empty bottles and then i would fill them with water from my base oasis and sell them with lots of bottle caps. Well, then i would be secured financially rest of my live so that is good plan i think.