I created these wallpapers series to make it easier to recognize Plasma activities and/or virtual desktops. I hope they can help you in your work.
FLAT Emulate Wallpapers can be used for activities related to other systems emulation: like VirtualBox, DosEMU, Wine, etc. Available in five different colours.
Sizes: 1920x1080 - 16:9 and 1920x1200 - 16:10