The horse looks fine to me.

Now, there's some very clever people here who know a lot more about this kind of stuff, but I've been well served by the Monitor Calibration Wizard...

http://www.hex2bit.com/products/product_mcw.asp

It's freeware and you can easily undo any changes you make if you don't like it, and you can even have different profiles, for example for daylight and nighttime.