I want to make a mochi theme, but don't know where to start. I saw the everforest theme someone posted but wanted to change the colors to make it revolved around purple. Any help would be great! Thank you!

Are you looking to theme the content of cards or the app itself? If the former, here's an example of a simple theme I created for myself https://github.com/brunomorency/mochi-remarks/tree/main

I would start from using a developer tool (ctrl + shift + I) to inspect class names and make CSS file on my own😅

For example, the main background color is from this CSS variable var(--mochi--side-bar--background)

We can upload our CSS to overwrite these values.