The flat colour is due to the fog that was prevalent at the time.
I made some adjustments in levels but too much and it lost the eerieness.
The space was left otherwise the building gets cramped and I also wanted to portray the sense of nothingness beyond the fog bank.
I did a BW conversion but prefered the colour version.
Fog mutes colour and to up the saturation and brightness would for me destroy that look.
I have another version of this where I blended the colour and BW version to mute the colours even more and I quite like that one.