# d2themes `d2themes` defines themes for D2. You can add a new one in `./d2themescatalog`, give a unique ID, and specify it in the CLI or library to see it. For example, to use the "Shirley temple" theme, which has an ID of 102: ```sh d2 --theme 102 in.d2 out.svg ``` Run `d2 --help` or `man d2` for more. # Themes overview # Color coding guide To distinguish container nesting, objects get progressively lighter the more nested it is. # Color coding example