Can you check if this still happens with Eclipse 4.8 instead of Eclipse 4.7.3a? Lots of color fixes have been added since Oxygen, and were not backported.
Here are the latest JBoss Tools builds, based on Eclipse 4.8 / Photon:
Note that JBoss Tools 4.6.0.AM2 should be released later today or tomorrow, based on Photon.0.M7 / Eclipse 4.8.0.M7.
In a week, the snapshot site will be updated to use Photon.0.RC3 / Eclipse 4.8.0.RC3 as we prepare for 4.6.0.AM3.
You can find the latest Photon EPP packages here: