Skinning Documentation
nemod comes with configuration variables that control how the game behaves. You can change any of them by pressing Shift+F1 to open the in-game console.
Of these, some are tagged SKINS; you can override those in skin.ini by adding a [neomod] section like so:
[neomod]
circle_rainbow: 1
slider_rainbow: 1
In this example, we're making the hitcircles and sliders change colors constantly.
If you are planning to distribute your skin to others, please remember that any convar you set will override user settings.