Enabling RGB mode for Dell displays on macOS

At least on my M1 MacBook Air, macOS likes to fall back to YPbPr color encoding for my external screen, a Dell P2415Q. With YPbPr encoding, the colors always look a bit washed out, especially noticeable in red text. To force macOS to use RGB encoding add a LinkDescription dictionary next to the existing CurrentInfo in /Library/Preferences/com.apple.windowserver.displays.plist:

cd /Library/Preferences/com.apple.windowserver.displays.plist
plutil -convert xml1 com.apple.windowserver.displays.plist

<key>LinkDescription</key>
<dict>
  <key>BitDepth</key>
  <integer>8</integer>
  <key>EOTF</key>
  <integer>0</integer>
  <key>PixelEncoding</key>
  <integer>0</integer>
  <key>Range</key>
  <integer>1</integer>
</dict>"

cd /Library/Preferences/com.apple.windowserver.displays.plist
plutil -convert binary1 com.apple.windowserver.displays.plist

Restart. Done.