There are many looks packages out there for FCPX, but they don't tackle some of the trickier colour correction problems that editors face. The new $25 HyColour colour grading utility plugin concentrates on getting the colours right.
Yes we all like looks, but they don't fix some of the more mundane colour corrections editors have to do. We have all received footage from cameramen that has been shot with the wrong filter settings or has a green cast from being shot under fluorescent lighting, so how can you get the colours back to true quickly?
HyColour is a $25 plugin for Final Cut Pro X that easily fixes those types of colour problems. Made by Jonathan Richards who shoots and edits his own material, he has given it a thorough testing before releasing it onto the market.