I am unable to use the "insert image" button ("an error has occurred"), so have uploaded two screenshots here:
1. http://i.imgur.com/paVyUCd.png (IDEA 14)
2. http://i.imgur.com/Sb459bm.png (IDEA 15 EAP)
Notice how the first, taken from IDEA 14 has a brighter background, and "thicker", more readable font rendering than the second, which was taken under the latest IDEA 15 EAP.
I've experimented with antialiasing options, changed underlying JDKs, etc, but cannot find a way to make 15 EAP look like 14.
Is this by design, or a setting I'm missing?