How do I access my custom themes? The pulldown only has mercury and tungsten. They exist in cakewalk content/sonar themes, but cbb doesn't see them. Is there another folder I can copy them into? Thanks. 

Yes the CbC folder is different than the Sonar folder and that is how they are named. Sonar Themes and Cakewalk Themes  they will both be in your Cakewalk Content folder. 
I do beleieve there is a case where you have to change the file extention but I didn't have to do that. 
I copied the Sonar Tungsten to the CbB folder ( cakewalk themes) and renamed it . This gave me back the original theme without the dark PVR. 

Delete: just saw a much better answer from Cactus.
 
 

Doh. Copied from sonar themes to cakewalk themes… thanks guys.