The Monster for this one actually resembles the Classic Universal look...
....Enough that when I first saw it when I was like 10 and knew nothing about Movie History I actually thought was part of the Universal series, and simply randomly colorized latter.
To be specific I placed it before Frankenstein Meets The Wolfman, as I actually thought the Castle in that resembles this one after it's Tower Burned down, certainly makes more sense then how we where supposed to think that was somehow the same building as The Modern looking Hospital in Ghost of Frankenstein.
I know universal has a Copyright to that look, and that's why Hammer couldn't use it in Curse of Frankenstein, but I also learned on The Board for Hammer's Mummy film that Universal made some sort of deal with Hammer after Horror of Dracula was so successful, so perhaps that explains why they did what they did here.
Also the way this is sort of infamous for not fitting in at all with the rest of The Hammer films, maybe the reason was they where trying to make would could be almost viewed as a lose Sequel to the Universal series, just still with Peter Cushing.
"It's not about money
It's about sending a Message
Everything Burns!"