I would add an option to upload a photo, and set it as a lunar client background
#Theme selector extensions
nimble roost
fluid thorn
nimble roost
a button that when you click lets you upload a picture from your computer, or add more lunar presets. Maybe like a single color or Purple - black fade and other.
or make some presets for the menu icons, like changing outline, background, text(icons) or let players set their custom colors