How can I get a grayscale effect in Kubuntu 18.04 using KWin?

Question

How can I use KWin to obtain a grayscale effect in Kubuntu 18.04?

Answer 1

Murat Çileli has developed KWin Grayscale Effect which, according to this reddit thread is

a fullscreen, configurable grayscale effect for KWin / KDE

If you want this effect,

• Download the tar and extract it.

• Run sudo cp -r kwin4_effect_grayscale /usr/share/kwin/effects

• Run sudo cp kwin4_effect_grayscale.desktop /usr/share/kservices5/kwin

• And edit the [Plugins] section of ~/.config/kwinrc to have kwin4_effect_grayscaleEnabled=true on its own line. In case the [Plugins] section is missing from your kwinrc, just add it.

To test it for the first time, open System Settings > Desktop Behavior. In there, open Desktop Effects. You should see Grayscale in the Appearance section. Toggle it a couple of times, and you'll see the grayscale effect at work.

Grayscale off:

Grayscale on:

Further configuration is possible. From the gitlab link:

A configuration file should be placed in /usr/share/kwin/effects/kwin4_effect_grayscale/contents/config/main.xml.

And available parameters are:

• ApplyInactiveWindowsOnly (boolean) : Effect applies to inactive windows only if it's set true.

• ExcludePanels (boolean) : Effect does not apply to panels if it's set true.

• EffectStrength (integer): Effect strength by percentage (%).