steel which perfectly absorbs heat. No, the best solution is to use aluminum.
Aluminum is far more thermally conductive and makes both a far better radiator and absorber of heat. Ultimately it’s a coating that does the absorbing though, as shiny metal reflects IR regardless of the material. Source: I work with this stuff
Light coloured or reflective roofs do make sense though and that’s why traditional homes in most hot climates are painted white.