I like the Aveda brand. I have had tinted gloss in my own shade and I don't have that many greys yet, but it did cover the few I have, but not for very long. I've never attempted home hair colour - I get everything done in the salon, it's safer that way - but basically yeah, they put it in a squeeze bottle and apply, wrap the head in plastic etc. For me, it lasts a long time (way more than the 8-12 washes or whatever they say) but it leaves my hair feeling in better condition - really soft, less noticeability of split ends, shiny, less frizz, more weight - and it loosens the curl a bit, especially at the root, which means longer, more "hanging" hair.
Get used to me. Black, confident, cocky; my name, not yours; my religion, not yours; my goals, my own; get used to me. -Muhammad Ali