Of course inks come in colours other than green; pick a colour, any colour and you can probably get it.
So you ask if tattoos come in colours other than green, then ask about black tattoos? ...Yeah. Pain is totally subjective, it depends on your tolerances, but I've heard it definitely isn't the least painful place to get one. I've seen truckers pass out from a tattoo on their shoulder, but a college girl not even bat an eye at their wrist getting done, so yeah, you'll find out how much it hurts if/when you get it.
Why would you blood turn a different colour? What the hell?