A quick web search for "define black" and "etymology blacklist" readily finds "from black (adj.), here indicative of disgrace, censure, punishment (a sense atte

A quick web search for "define black" and "etymology blacklist" readily finds "from black (adj.), here indicative of disgrace, censure, punishment (a sense attested from 1590s, in black book)" and several similar results. But I didn't immediately see an etymology based on absorbing light. I'd be curious to see a regional reference that shows an absorb/reflect etymology.