I know we've debated red springs vs. white springs and how to tell these apart. But here's one thing. On the outside, whites turn grayish green and reds turn reddish. Is that because the beta-carotene in the flesh comes out into the skin with the reds when they mature? And since whites lack this in their flesh, they just go dark gray, green, then eventually black. Thought I'd ask the quick question to see if anyone know this off hand. Other salmon that turn red are the sox and coho of course - both of which have rich red flesh. Steelhead and rainbow trout (interior) also turn red and these also have red flesh. Pinks and chum don't turn red - but I've noticed that their flesh is very pale in colour. OK - I need to think about something else.......