When I see my white hairs turning reddish or brownish, I get my 10X Microscope that I bought at Radio Shack and look at the trichomes.
AND
Harvesting Too late is better than Harvesting too soon.
It's very hard to tell with the HPS bulb throwing off the orange/yellow light. I can see one thing though, looks like you have/had a pretty bad case of spider mites. It looks like their are destroying your plant. Have you treated your plant for spider mites? Check out the spots I have marked on you picture.