In Dead Center, after that orange fuel tanker is blown up, the chunk still hitched to the truck shows up entirely orange.
Probably because it's part of the truck model. Since the truck is colored orange, that part of the trailer is orange colored aswell.

While you're at it, you should maybe remake the texture for when the tanker is destroyed.
It looks like somebody just used the airbrush tool in MS Paint and called it a day. Plus there are weird green patches in the soot and ash.

I have not noticed that color issue, but i can fix that.
The green patches could be the compressed texture itself. Black likes to bug out and turn green. I won't add a reskin here though, that would make other skin mods incompatible

There is a purple sofa model that has a corner of the texture rendered wrong on it. (models/props_interiors/couch.mdl) There is a black square of blank space near the bottom of it. I believe the model is used in Death Toll Finale near the military house and a few trailers in the L4D2 campaigns.

ah yea. case of bad uvmapping.
that's a simple fix

Fences from Death Tool's last map

@мяFunreal
For me dock in Death Toll finale has bugged model:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2318115371
Checked in Hammer editor and model is dock01_polecluster01d_256 located in models\props_docks
Im running this game on low memory setting so that could be the reason. Also I checked and I dont appear to have any mods which should change this model either so can you please take a look and see what you can do about this? Thanks in advance.

turns out the LOD model (Level of detail - for models that are usually further away) just has missing faces there. which is a simple fix
i'll put that on my to do list

and now its fixed.

@мяFunreal Well that was quick. Thank you!

https://steamuserimages-a.akamaihd.net/ugc/1798604069326689885/E521C0017312383B63AD2B75CAB90917E70710E4/
Hey can you fix this side panel truck ? ( sorry for my english bad, and I don't know how to use hammer editor.)

I can. But i don't think it's broken. They wanted it to look like that.

Done https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2509678622

It might be caused by it clipping into another model and not getting proper lighting, because the map could have been compiled incorrectly.
But i'll check if there's anything i can do to fix this, if a reskin alone cannot.

I found another one! the 2 Burger Tank signs (models/props_signs/burgersign.mdl and burgersign_beacon.mdl) both have some strange lines in the textures on their models. I'm not sure if that would be an easy fix or not.

It would be easy to fix, since it is just a texture issue