OS X 10.6: sub-pixel antialiasing

I'm using a Core2Duo Mac mini with the latest OS X 10.6 version. Though the option "Use LCD font smoothing when available" is selected in the System Preferences, Appearance page, when I take a screenshot and zoom-in only gray text is shown, no colored borders on the fonts.

How I can activate LCD sub-pixel antialiasing on OS X 10.6?

OK, I've found the solution at welp's blog: just execute following command

defaults -currentHost write -globalDomain AppleFontSmoothing -int 2

Actually I don't see a difference neither: With LCD smoothing turned on:

With LCD smoothing turned off:

If you look at the 'y' you clearly see that the subpixels have all the same brightness. Thus they are just shades of grey.