There's a lot on the market for this, as you'll find out from Google.
There are a lot of colour coded keyboards for particular editing software that many editors like, YMMV.
I've used the Countour design Shuttle Pro jog/shuttle controller a lot and prefer that myself. It can be programmed to work exactly how you like and can also be used with other programs, eg Lightroom to aid productivity too.
The one problem is the terrible support from Contour. Great if it works on your system, but eBay fodder if it doesn't.
I reported a bug with it's software for Windows 7 64bit (confirmed by others) in April, but no fix has been offered yet.