message: fix index mismatch
diff: @@ -124,15 +124,15 @@ $pinned-unread-color: var(--warning-color);
  $warning-color: var(--warning-color);
  $button-danger-disabled-bg-color: var(--warning-color-50pct); // still needs alpha at 0.5
  //
  -// --username colors
  -$username-variant1-color: var(--username-colors_1, $username-variant1-color);
  -$username-variant2-color: var(--username-colors_2, $username-variant2-color);
  -$username-variant3-color: var(--username-colors_3, $username-variant3-color);
  -$username-variant4-color: var(--username-colors_4, $username-variant4-color);
  -$username-variant5-color: var(--username-colors_5, $username-variant5-color);
  -$username-variant6-color: var(--username-colors_6, $username-variant6-color);
  -$username-variant7-color: var(--username-colors_7, $username-variant7-color);
  -$username-variant8-color: var(--username-colors_8, $username-variant8-color);
  +// --username colors (which use a 0-based index)
  +$username-variant1-color: var(--username-colors_0, $username-variant1-color);
  +$username-variant2-color: var(--username-colors_1, $username-variant2-color);
  +$username-variant3-color: var(--username-colors_2, $username-variant3-color);
  +$username-variant4-color: var(--username-colors_3, $username-variant4-color);
  +$username-variant5-color: var(--username-colors_4, $username-variant5-color);
  +$username-variant6-color: var(--username-colors_5, $username-variant6-color);
  +$username-variant7-color: var(--username-colors_6, $username-variant7-color);
  +$username-variant8-color: var(--username-colors_7, $username-variant8-color);
  //
  // --timeline-highlights-color
  $event-selected-color: var(--timeline-highlights-color);
  