GOZR, good point about everyone's monitors being calibrated differently. It's impossible to make settings that will suit everyone.
There are some universal standards people can try to align themselves to though. In my case, I'm using a colour calibration tool to get my monitor very close (~90%) to one of the RGB standards (can't remember which one).
This is what my game looks like (using my SweetFX Neutral6 settings at 9am) with my monitor unadjusted and adjusted (unadjusted/uncalibrated is the first picture and adjusted/calibrated is the second picture).
Seeing this, it's easy to understand how some people must think my SweetFX colours and brightness levels are off. I saw some screenshots from the Sukhoi forums the other day and indeed, my SweetFX settings look very different on their systems/monitors (like the screenshots above, or worse).
About the "SweetFX on it's own doesn't work with 64-bit executables." comment, I think someone else said it's not a problem because IL-2 Sturmovik: Cliffs Of Dover is a 32-bit game anyway.
If the SweetFX utility isn't working for you, perhaps try re-installing it without the 'd3d9' .dll file and/or the 'd3d9.fx' file, as they were causing problems with some people.