90 Shades of Black
Agent Shade, who made this one, is a friend of mine; she seems a dark character at first impression, but that changes as you get to know her.
The answer is an English word. You'll know it's right when you have it. To check your answer, remove the trailing slash from this page's URL and add "-xxxxx", where "xxxxx" is the answer in all lowercase. If you've tried it and are really stuck, the solution is here, though I'd ask that you feel slightly sheepish when clicking the link.