Weird colors on secondary monitor When I connect my macbook air (2012 early I think) to a DELL U24-something display through a DVI the colors on the display are really weired: it is like all the colors are really desaturated and low-contrast and some selected colors are very saturated and strong.

I tried changing color profile but then it only got worse.. when I have a Windows PC connected the colors look great.
Every time I have had a color problem with an external monitor the problem was caused by a loose/bad connection between the display's cable the and display adapter dongle on my Mac.  Make sure the cable is firmly and completely seated inside the port on the dongle.