material_base-8.x-2.x-dev/themes/material_base_subtheme/config/schema/THEMENAME.schema.yml

THEMENAME.settings:
  type: theme_settings
  label: 'Theme name settings'
  mapping:
    navbar_fixed:
      type: boolean
      label: 'Sticky navbar'
    navbar_style:
      type: string
      label: 'Navbar style'
    drawer_style:
      type: string
      label: 'Drawer style'
    drawer_height:
      type: string
      label: 'Drawer height'
    footer_style:
      type: string
      label: 'Footer style'
    messages_fixed:
      type: boolean
      label: 'Messages in overlay'