Fixed minor theme issues

As I'm running a dark KDE theme I had some ui issues.
This pull request contains some font color fixes

Before:
![before](https://cloud.githubusercontent.com/assets/4720529/3870753/f7d99c40-20dc-11e4-9958-6c8ba996fa99.png)
After:
![after](https://cloud.githubusercontent.com/assets/4720529/3870755/0058af78-20dd-11e4-8d1b-0a81e27e577a.png)