I don’t really think your reasoning is correct. I think it’s more that Victorian fashions (and later) favoured those drab colours. Compare to eg medieval dress

I don’t really think your reasoning is correct. I think it’s more that Victorian fashions (and later) favoured those drab colours. Compare to eg medieval dress which was colourful (though limited by dyes) or the way old (catholic) churches were decorated. You can see the brightly coloured roofs from Red square for example. It was just taken on an overcast day with a 70+ year old camera. I think part of the drabness is limited by the technology, in the same way that Turner’s paintings are less colourful than those by Van Gogh. Another thing is the soot in the cities making everything generally dirty and perhaps also causing people to prefer darker outer layers.