I saw a program on Avid's forums. It may be useful to you.

https://duc.avid.com/showthread.php?t=415078

 

it would be awesome if the guy can make some sort of similar tool to manage the dark theme on older versions of protools (like 12.5)... or add a feature to the current one, because the light theme is not really good as the only option now hahahahahahahaha

 

As far as I can see, they are still tweaking the dark mode. Users didn't fully satisfied with it. I will write to him about that and maybe he will look into it.

 

oh yes, it isn't perfect i agree.... but having the option of apply it as it looks on newest version of protools would be awesome (with the obvious replacement of files... if that may be a requirement), because with just replace the files on the older ones, it looks like shit hahahahah