I have had great experiences using Dav-Tech in Marlborough MA.
Metal Finishing Company Quality Metal Finishing Service Services Precision Metal Finishing
I have used them for black & blue anodize, and colored hardcoat. I did visit with a salesman about a year ago, and I recall they had about 40 or so standard colors.
Thier turn-around time is usually less than a week as well.
They do have minimum pricing though, so if it only a handful of parts, it may be costly. I would think that that would be true of almost any plating house though.
I am not affiliated with them in any way, but they have treated me very well over the last 10 years, at two different companies where I have worked here in southern NH.