I have never been very good at doing my tires often, and it is especially a chore now since i got 38s a few weeks ago. Anyway, when i scrub them, i use a bucket of soap/water just for the tires, tire brush and some simple green (cant get the costco apc yet). I spray the whole sidewall down with SG, let it sit for a moment and then get to scrubbing with the brush, then with the soap/water as well. I scrub pretty well i think and it looks like a lot of junk is coming off the tires (water/foam is yellowish brown). However, when they dry they are very browned up and if i swipe my finger across them, brown, dirty residue comes off. I have never dressed these tires yet (like i said, only had them a few weeks). Are they just brown due to a lack of dressing, or did i not get them clean enough. Should they be all black without dressing, and just a deeper black with dressing?