How to get the average wallpaper color (accent color) in KDE, just like Unity?

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1

In GNOME based environments, under X11, the average background color of the wallpaper can be obtained with

xprop -root | grep _GNOME_BACKGROUND_REPRESENTATIVE_COLORS

It gives an output like

_GNOME_BACKGROUND_REPRESENTATIVE_COLORS(STRING) = "rgb(65,70,61)"

This is the method Unity used to make the dash have the same color as the wallpaper.

However, xprop does not work in Wayland, and _GNOME_BACKGROUND_REPRESENTATIVE_COLORS would not work in KDE.

Is there any way to get the average color/accent color in KDE with Wayland as well as X11?

I want to use this color to make an app have ``chameleonic" background color.

2

Kirigami has this function, but I’m not aware of a command-line tool to get it easily.

However if you’re writing an app, you don’t want to use that anyway; you want to use the proper API to access the functionality! You can access it with Kirigami.ImageColors. See the examples in examples/Image Colors · master · Frameworks / Kirigami · GitLab.

The only challenge here will be getting the wallpaper to use as the source. I’m not immediately sure how to do this.

3

I found another method that works in wayland as well as X11.
The command

gsettings get org.gnome.desktop.background picture-uri

gives me the location of the wallpaper image. Then, I can use imagemagick to get the color

convert "$(gsettings get org.gnome.desktop.background picture-uri | sed -e "s/'file:\/\/\(.*\)'/\1/")" -resize 1x1 txt:- | awk 'NR==2 {print $3}'

Similar methods would work for Cinnamon, MATE and XFCE as well.

Does KDE store the location of its wallpaper somewhere?

Then I can write a simple script in my code to extract the color for every desktop environment.

4

It’s not quite that simple, since the active wallpaper may not be an image; we support arbitrary wallpaper plugins.

But if it is an image, you’ll find it in ~/.config/plasma-org.kde.plasma.desktop-appletsrc. Search for Image=.

Keep in mind that each screen has its own wallpaper, so you might find several.

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5

You did say “an app” not “my apps” so I guess maybe you’re actually developing something new here, but if it’s the end result you’re after, there’s GitHub - luisbocanegra/kde-material-you-colors: Automatic color scheme generator from your wallpaper for KDE Plasma powered by Material You

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6

Just like Nate said, getting what is actually being displayed is not that simple for wallpaper plugins that aren’t a simple static image/color, the way I ended doing it for kde-material-you-colors was with a desktop screenshot fallback but even that isn’t perfect, see Getting wallpaper from Plasma is complicated and prone to errors · Issue #187 · luisbocanegra/kde-material-you-colors · GitHub

I think for this to work reliably Plasma would need to provide a method to query the current view of the desktop background as an image. There is also qdbus org.kde.plasmashell /PlasmaShell org.kde.PlasmaShell.color but that one requires enabling accent color from wallpaper in the color scheme settings.

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7

Thank you. That should cover most use cases

Not quite. I recently rewrote this weather app (Typhoon), and I want to add a Chameleonic background feature.

Thank you all. I will get back if something goes wrong, and will post when the feature is ready.

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8

I wrote this function to extract the path to the wallpaper

and this lines of code turn the wallpaper into a color code using imagemagick

The app was recently featured in OMG Ubuntu Developer Revives Iconic Desktop Weather App for Linux - OMG! Ubuntu