Starting with Cycle version 2.5.0 you can now give your eyes a break by switching the Cycle client to Dark mode!
Dark mode in Cycle keeps all of the same functionality and syntax highlighting in place but replaces the bright white background with a dark background.
Toggling Dark mode on and off
There are two methods for switching between light mode and dark mode in your Cycle client: Application Preferences and the Sun/Moon icon.
By going to Edit>Preferences in the menu and scrolling down to the Appearance section you will find the setting for Color Mode:
You can also toggle light/dark modes by clicking the sun/moon icon in the bottom right corner of Cycle: