Do all the liveries work in P3D?

The ones through op centre, yes.

Forgive me, is the op centre the PMDG sight that lists the liveries for FSX? 

Disregard, found it.

Do liveries downloaded via avsim work with P3D v3?

Should do but it's not guaranteed.

Should do but it's not guaranteed.

I don't see why they wouldn't. Never had a problem with compatibility. 

I don't see why they wouldn't. Never had a problem with compatibility. 

Only reason I could think of is dx9 vs dx11 causing issues.

I am surprised that PMDG does not have a Southwest in their current paint scheme.

I am surprised that PMDG does not have a Southwest in their current paint scheme.

It's because the NGX came out before that livery was implemented, and PMDG has no reason to add it themselves when there's plenty available here on avsim and on other sites. 

True.  I installed many from the library with FSX but not sure how to do it with P3D.

True.  I installed many from the library with FSX but not sure how to do it with P3D.

The exact same way..

I'm certainly no expert at this but I did a peripheral look at P3D files.  It is set up much differently than FSX.  I could not find a plane config file. 

 

Has anyone actually done it?

I'm certainly no expert at this but I did a peripheral look at P3D files.  It is set up much differently than FSX.  I could not find a plane config file. 

 

Has anyone actually done it?

 

The process is exactly the same. Find liveries on avsim that are in a ptp format and use the op centre to install the livery. Don't go fiddling about with aircraft.cfgs and whatever else, let Op Centre handle everything. What I meant by it not working is there might be graphical issues if the creator has modified things like alpha layers etc. Install should be identical. If you're using the P3D NGX in P3D, op centre should do it all for you.

Thank you!  I'll try it.