Please add an option to disable transparency of panels when Breeze theme is used. This option should include alt-tab window swithing panel, menus, and all other stuff. I find it very distracting when white panel overlaps window with few icons and I can see additional icons in my task list. Thank you! Reproducible: Always
Transparency or not is a choice of the theme. There are plenty of themes without transparency which you can choose on kde-look.org
Additionally, disabling compositing will remove several distractions, including animations, as well as removing transparency. One thing we could do is add an intensity option slider to the Kwin "Background Contrast" effect; with the extreme intensity effectively drowning out the background completely, only picking up a small amount of colour.
Note that disabling composting takes away many benefits of offloading graphical computations to the GPU; it also is not possible on Wayland. Additionally, background contrast intensity is also a determined by the theme.
Ah. I thought there are options for a theme just like there are options for window decorations. Sorry. I do not want to disable compositing because I would loose desktop grid and present windows effects which are very helpful. Background contrast effect seems to help a bit. But it sounds like fixing a fix of something which is not broken :) Is it possible to add such slider or checkbox to desktop theme settings, so it could work with any theme?