Comment 2 for bug 560331

A workaround (really not a fix) is the following:
- Open /usr/share/pixmaps as root (gksu nautilus /usr/share/pixmaps)
- Right-click on the tasque-XX.png files -> open with -> gimp
- Not sure how the actions in gimp are exactly named in english, but it should be something like image -> mode -> grey scale
- Save the grey scale version
- Quit and restart tasque

The files probably will be overwritten with new tasque versions, so you might want to store the grey ones somewhere and copy them over if you make an update