The "Opacity" slider on KDE Screen Ruler controls the color and not its opacity: when the slider is all the way at the left the ruler is black, when it is at the right the ruler is yellow with black markings (default colors). Is there any way to make the ruler transparent?

BTW: Is there any way to make the ruler narrower than its default width?

Hardware 4 cpu x86_64
System Fedora-16 with all updates installed
KDE 4.7.3 running on 4 cpu x86_64 hardware.
KDE Screen Ruler version 4.7.3
Graphics system NVidia GeForce 9500 GT using the nouveau driver

Do you have composite (desktop effects) enabled? It's required to get transparency. A good idea would be to hide the opacity option when composite is disabled, you might want to file a wishlist at http://bugs.kde.org.

I can make the ruler slightly narrower by resizing manually (I've set Alt+right mouse button to resize in System Settings -> Window Behavior -> Window Behavior -> Window Actions).