The collar of wolves differs in color depending on whether they're standing or not

The Bug:

The collar of wolves differs in color depending on whether they're standing or not.

It appears that the collar of a wolf looks lighter if they're sitting and darker if they're standing.

Steps to Reproduce:

1. Summon a wolf, tame it, and make it sit.

2. Take note of the color of its collar.

3. Make the wolf stand and take note of the color of its collar once again.

4. Take note as to whether or not the collar of wolves differs in color depending on whether they're standing or not.

Observed Behavior:

The collar of wolves differs in color depending on whether they're standing or not.

Expected Behavior:

The collar of wolves would not differ in color depending on whether they're standing or not.