You provided 1 quote. So I'm not claiming it's just 1 fan. It is 1 fan. If you can find thousands more (a SIGNIFICANT number), then I will accept that a significant number of Charlton fans support Powell thanks to his skin colour. Until then, the only conclusion is that Charlton fans support Chris Powell thanks to his record with us, as you can see on here and on CL.
Yes, what are our double standards?
Steve Gritt and Keith Peacock are both Charlton legends. Why would anyone think otherwise? Powell is too, thanks to his 250+ appearances for the club, most of which were in the top flight, and now his tremendous first 2 full seasons as manager. Do you think Powell doesn't have an affinity with the fans? I while ago I mentioned the interview he gave at Carlisle, where you can see the tears in his eyes. There are his speeches at the Player Of The Year dinners for the past two years as well that are worth watching if you doubt his affinity for the club and the fans (they are available, if not online then on the Season Review DVDs).
Alan Mullery is a rubbish comparison. Charlton fans are proud of Chris Powell's England caps because he won them while he was a Charlton player. Unlike Mullery, who won all his at Spurs. More importantly, Mullery was manager for one season (81/82) in the second tier and we finished 13th, so his record as Charlton manager is not as good as Powell's.
Your last paragraph WOULD be a good point, IF you could prove that that is what Charlton fans are doing. The onus is on you to prove it, and 1 quote is not enough I'm afraid.