How Do I Edit/Modify My Own Theme?

Simple 101 question.

I quickly developed my own theme on the fly and now I want to tweak the colors. I thought maybe it was as easy as navigating to the theme in the developer hub and tweaking some settings in it. Instead, not only can I not figure out how to get to this, or whether the possibility even exists, but I can’t find any threads or documentation on how to do it in the first place. This can’t be the first time in the history of the world someone has asked this question, can it? :laughing:

Did you use Firefox Color to create the theme?

I used whatever platform Firefox provides in their developer hub.