I also have 2 monitors.
Main: NEC 2190uxp a very expensive monitor that displays great color. It has an S-PVA panel type.
Second: Crappy Dell 19", no matter how much time you spend on it you will never be able to adjust it to display colors correctly. TN panel type. But its good for a second monitor.
Monitor color quality is all based on panel type.
Find out the panel type for your monitor:
Description of panel types:
http://www.flatpanelshd.com/focus.php?s ... 1229335030
When I was adjusting your image I used the color picker to display the color of the pixel it was over. I could see the red was higher than the others in the gray area of the bottom plate. I know that with gray all the numbers should be equal. So I used the ColorBalance panel to equalize those rbg numbers as best I could. So my monitor helped to see the true colors but I was going by the numbers while adjusting.
Of course most of the time you wont know what the color is supposed to be.