What Blu said and don't use a Rub that's too heavy in sugar, I was doing some experimenting with 4 different Rubs the ones to the left had a higher sugar content than the ones on the right. Cooked these at 275 unwrapped no spritz, no mop, all of them were good eating just the presentation was a little better with the 2 on the right.
As long as "dark" ain't "burnt"- I can't see where it matters too terrribly much. I'm going for taste...if you are trying to make some judge happy in a comp -well that's a different thing. Easing off the sugar will help, especially if you are running 325 up. :-D