[Qt-creator] Ugly font rendering?

[Nikos Chantziaras]

I was using Qt Creator 2.8.1 and decided to try 3.1.1. So I installed it 
using the official Linux installer.

The fonts look "washed out" and lack blackness, making them tiring to 
read. Here's how fonts look in Creator 2.8.1:

   http://s15.postimg.org/es4jn3xdn/qt4.png

and here's how they look in 3.1.1:

   http://s28.postimg.org/lic77ee25/qt5.png

Is there anything I can do about this?