The Bug:

Frozen, poison, wither, and hardcore hearts are displayed as normal red hearts on the tab list.

This issue can only be seen with frozen, poison, wither, and hardcore hearts. Absorption hearts and normal red hearts are displayed correctly on the tab list. This may be considered as a feature request but since absorption hearts are displayed correctly on the tab list, I'd expect the same behavior for all of the other heart textures.

Steps to Reproduce:

1. Create a scoreboard objective for tracking your health and set it to display on the tab list by using the commands provided below. 

   /scoreboard objectives add health health

   /scoreboard objectives setdisplay list health

2. Give yourself the poison effect by using the command provided below.

   /effect give @s minecraft:poison

3. Hit TAB and look at your health on the tab list.
4. Take note as to whether or not frozen, poison, wither, and hardcore hearts are displayed as normal red hearts on the tab list.

Observed Behavior:

Frozen, poison, wither, and hardcore hearts are displayed as normal red hearts on the tab list.

Expected Behavior:

Frozen, poison, wither, and hardcore hearts would not be displayed as normal red hearts on the tab list. Instead, they should be displayed accordingly. For example, if you are poisoned, poison hearts would be displayed on the tab list.