edit: https://www.abc.net.au/news/2018-12-16/egypt-unveils-one-of-...
edit: https://www.abc.net.au/news/2018-12-16/egypt-unveils-one-of-...
How can you not mention egypt's own royal tombs, which were chock full of rich artwork (somewhat we know because several KVs still have lot of artwork) e.g. https://en.wikipedia.org/wiki/File:Egypt.KV62.01.jpg in KV62, which is considered "modest wall decorations", or https://en.wikipedia.org/wiki/File:Egypt.KV43.01.jpg from KV43.
This is actually an interesting point by people who argue the Great Pyramid is not a royal tomb...all other royal tombs are richly decorated, whereas the chambers in the great pyramid are noticeably bear.
I always understood the white polished casing stones were not painted but did have carved hieroglyphics (I think this is how they have identified some of the reused stone in mosques for example). On the other hand, the Sphinx still has some blue and yellow paint on it.
In parts of Pakistan at least (where I was born) there is this sense of fairness of skin being a desirable trait (goes almost without saying that it is not a belief I endorse at all). I can imagine such unrealistic beauty standards echo through the centuries.