Why aren’t the “fronts” of satellites (the parts that can reflect light towards earth) coated in something like vantablack? If heat absorption is the issue, put a big heat exchanger on the back. It seems weird to try and come up with high-tech solutions when we already have compounds that would likely reduce light reflection significantly. It wouldn’t be a one-size-fits all solution, you’d still have to figure out how to orient solar panels to not reflect light towards earth, or how to dispell the excess heat, but I’d hope it’d dim them significantly.