Danny,
It's been awhile since I worked in the asphalt business (did it during the summers in college), but I might be able to offer a little help.
Yes, asphalt driveways can be painted. I've seen them done in <font color=green>green</font color=green> and <font color=red>red</font color=red>. I don't know if there are other colors available, but I suppose you could mix the two and get brown (?). The paint that we used back then was also a sealer, so we killed two birds with one stone. I don't know how much it cost. It just showed up on the job site and we used it. Must've been free, huh?
The most common reason people seal asphalt is to make it look pretty again. In most cases, that's black. But actually, sealing helps keep weeds from growing through cracks, etc. It also reduces (not eliminates) cracking, and will make the surface a little harder so that motorcycle and bicycle kick stands don't sink into the soft asphalt as quickly. I'm sorry, but I can't help with the cost. I do know that most of the big name hardware/home improvement stores do carry asphalt sealer, at least in black.
Remember one thing about asphalt. Unless you have some kind of border along the edges, asphalt will begin crumbling faster on the edges, even if it is sealed.