Freeware from Jonax
Grayout-for-Linux
Coded with Lazarus Pascal
Compiled on 64-bit Debian GNU/Linux (13.0 Trixie)
Place the file in some directory
If necessary make executable.
Run the program
Download size: 2.8 MB
System Requirements: Linux, GTK2, 3 MB free disk space, mouse, monitor >= 1024*768 pixels
GTK2 is no installed by default on newer distributions. E.g. Debian 13. Can be installed with
sudo apt install libgtk2.0-0
What to do:
Paint the world gray in the available number of steps. Choose right neighbouring color to eliminate

^ Animated GIF / Screenshot of Grayout for Linux
SHA512:
e589d759d2acf730dc653bb1aae2243bd24d7e7508dcad580d0e3ec070ec7f5a9503d76df2941a43f5740bb3f3c577344a253141519fdc87b07bc18ddd8cf56f
Download Grayout here