So that you can change the color and if it's transparent or not.
This is what we have Plasma themes for. You can choose one that matches your preferences better.
(In reply to Nate Graham from comment #1) > This is what we have Plasma themes for. You can choose one that matches your > preferences better. But you can't change the theme just for the task bar or am I wrong? Then the problem here is more that you can't select a different theme for each kde part separately.
That's correct. There's a balance to be struck, for sure. I understand that it might seem odd to create or replace your plasma theme when you want to just change one thing. But the idea of Plasma themes was to allow people to self-satisfy without having to expose every single visual option which would make the UI insane and buggy. Or at least, even buggier than it already is. :)