Comment 21 for bug 443311

So let me summarise how these icons are used and what we expect:
- gnome-display-properties: used in display-properties.desktop for the menu entry and the gnome-display-properties binary for the notification area, expected to be colourful when used in application lists,
- display-capplet: no idea where this is used
- gsd-xrandr: used in gnome-settings-daemon's libxrandr.so plugin for the notification bubble

So the expectations for each icon as I see them:
- gnome-display-properties: colourful when size 48, grey scales when size << 48
- display-capplet: no idea
- gsd-xrandr: I'd guess grey scales all the time

What's in lp:humanity right now:
- gnome-display-properties: always a real file, colourful at size 24 and 48, only in Humanity
- display-capplet: symlink to gnome-display-properties at size 24 and 48, only in Humanity
- gsd-xrandr: real file at size 22 and 24, and at size 48 in Humanity-Dark, symlink to display-capplet at size 48 in Humanity, colourful at size 48, grey scales at size 22 and 24
./Humanity/apps/48/gsd-xrandr.svg