For some reason, loading into a rundown lobby with the "STRP Pack Mule" backpack equipped causes it to appear as if it were under the effect of the "Lugubrious" Palette regardless of which Palette is equipped. This is shown in the far left of the attached photo.
To replicate this and maybe figure out why it happens, equip the backpack whilst in a lobby and press "Rundown" on the top tab, then switch back to the "Lobby tab".
This bug only occurs when switching tabs, and has not occurred for me on the original start-up of the lobby, I have only been able to replicate it with this backpack however the shader used does not matter as it can occur regardless of shader.
I do not know if it stays this colour when in the actual mission as I found this when playing alone and cannot check it with someone else.
Upon selecting "Apparel" and then closing the menu it brings up, the bag returns to the intended palette.