Dell U2410 HDMI + OS X Lion very poor quality Having plugged my MacBook Air (Mid-2012) into a Dell 24" 2410 monitor, the quality is terrible.

For reference the same monitor plugged into a Dell XPS M1330 running Windows 7 via HDMI give nice results with zero configuration.

I found some ICC files and tried them and found things like reds not being bright or strange gamma and contrast problems. I tried suggested brightness and contrast settings and RGB values and reset the monitor back to factory settings.

How do I get the same results or better than Windows or some other arbitrary HDMI device? I want OS X to at least best an upscaling DVD player.
The problem was caused by OS X outputting in YPbPr not RGB. YPbPr sends approximate colours and is used primarily for TVs. Unlike Windows, OS X didn't recognise the Dell as a Monitor because of the HDMI connection. Shifting to a DVI connector fixed this and forced RGB colour data, and thus, correct colours.

So no, it was not a problem with callibrating the monitor or its colour profile