issueNumber: MDL-83725
notes:
  theme_boost:
    - message: >-
        From now on, themes can customise the activity icon colours using simple
        CSS variables. The new variables are $activity-icon-administration-bg,
        $activity-icon-assessment-bg, $activity-icon-collaboration-bg,
        $activity-icon-communication-bg, $activity-icon-content-bg,
        $activity-icon-interactivecontent-bg. All previous
        `$activity-icon-*-filter` elements can be removed, as they are no longer
        in use.
      type: changed