Yes of course - there have been a real great budget for GCI work within this production (the matter that any GCI budget is allways to low doesn't care ...... buy the way

).
But the main issue was : The original colors from that 20 years era are not known from reality by most of us. So we may regard such bw movies from that epoche and can not realize the fact that the 20th may had no different colors like today 2018.
That indeed was the intention of this movie (from color grading) to show a LOOK that isn't like that well known "dirty" color matching from other films regarding the 20th in color.
The colors here might have an artificiell substance that allows to dive into the scene. Theoreticaly it might be a play far from now in 2021 !
with regards