Here are the instructions if you prefer a blue accent color over the default orange:
- Quit Agenda
- Open the app Terminal, which is in /Applications/Utilities
- Copy this into Terminal, and press return
defaults write ~/Library/Containers/com.momenta.agenda.macos/Data/Library/Preferences/com.momenta.agenda.macos useSystemBlueAccent -bool YES
- Run Agenda again and see if it indeed has the blue accent color (requires version 5)
For completeness, to restore Agenda to use the default orange again you can repeat the above but instead use the command:
defaults delete ~/Library/Containers/com.momenta.agenda.macos/Data/Library/Preferences/com.momenta.agenda.macos useSystemBlueAccent