It's slightly different, but barely noticeable in most parts. But thanks to you I found something else I like:
winbox.exe -platform windows:fontengine=gdi
It actually respects system settings, so with ClearType off it's nice and sharp / pixelated, and with ClearType on it's whatever is set there. It's not perfect, bold texts are still rainbowy, but I can "unbold" them using Bold slider in WB settings. It doesn't affect bold texts on buttons, but the rest of WB is fine, so I'm now much happier. Well, at least until someone from QT decides that GDI is too obsolete and removes it.
Now if I could only do something about those UI colors (it's just too bright for me), I'd be finally able to focus on functional things. 