Anyone know how to transfer a custom cpanel theme to a new server?

I think you can do this from WHM under the themes section.

Don't have WHM up right now but think I seen that before.

I tried using SCP but getting an error that the file is "not a regular file".

The file looks like so: theme_name@

Have you tried a search or post on the cPanel forums?
There should be a lot of other people that have already done what you want to do there.

I don't have a custom cPanel skin so I haven't exported any themes and I don't have WHM here right now.

Good luck
John

The cpanel forums were the first place I went to. Nothing there.