The text background opacity accessibility option doesn't properly affect the tab list

The Bug:

The text background opacity accessibility option doesn't properly affect the tab list.

Altering the "Text Background Opacity" slider appears to change the opacity of the box behind a player name but not the box behind all player names.

Steps to Reproduce:

1. Navigate to your accessibility settings menu and set the "Text Background Opacity" slider to "0%" and the "Text Background" button to "Everywhere".
2. Join a multiplayer server or LAN world that has other players currently online.
3. Press and hold the TAB key and look closely at the tab list.
4. Take note as to whether or not the text background opacity accessibility option properly affects the tab list.

Observed Behavior:

The text background opacity accessibility option doesn't properly affect the tab list.

Expected Behavior:

The text background opacity accessibility option would properly affect the tab list.