Art question

I notice that, Amarna period to one side, I can't tell Egyptian tomb art from one era from that of another--it all seems to reflect the same forms and ideals. Although my Better Half can testify that my color sense is idiosyncratic and I presume my artistic judgment is therefore somewhat suspect, I'll assume that their art styles really did stay the same.

That would imply one of two cases: the styles didn't change substantially over 2000 years, or the tomb art, representing an ideal world, no longer reflected what people actually wore or used.

Unfortunately I'm having trouble finding representations of Egyptians from other cultures, except as captives (who aren't usually dressed in their finest). Roman era Egyptians dressed differently than the Egyptians in the tomb art.

Does anybody with a little more familiarity with ancient Egypt know about this?