for the icons, backgrounds, and font colors

Got to Studio > Your Theme (Lucid / Protean) > Styles> Select the Mode ( dark / light) and then edit the values you would like to change.

You can also set custom fields.

I was using artificer, and it didn't have these options. I set protean as my default, but it is not letting me change those options nor am i seeing these template layout changes on the site