Hi
I am a longtime user of kde. I have always loved it because you can make it look and feel exactly the way you want.
Now with plasma desktop themes you can easily install new ones from the kde store. And still I have a wish:

I would like it very much if there was a plasma desktop theme that came with the possibility to change its color and opacity just by using sliders and color pickers (I mean in an easy way). In Windows (10) you can chose the overall color of the system and in Gnome 3 you can choose the color and opacity of these desktop elements very easily..
I think it would be great if there was such a possibility in plasma 5 too.

Thank you for you time and thank you for the FANTASTIC work on this great desktop environment.

They would need to create a new theme for this, since right now the Breeze theme inherits elements of the color scheme (window background and text colors, I believe), and personally I prefer this over manually adjusting the color since it gives the desktop a consistent, matching feel, which you loose if you independently choose the color of your desktop theme.

That said, it would be cool to have another theme that allows manual adjustment of color and opacity.

What about just updating the Breeze theme to support customizing the transparency via the suggested gui? That it derives its colors from the system color scheme may be sufficient for that part of begonia's request.