"The River Seine was a silver-blue blade bisecting the city"
...............

Lucien watched...the sunrise break the horizon, turning the River Seine
into a bright copper-coloured ribbon across Paris."

From Sacre Bleu by Christopher Moore

I guess the river inspires in various colours.

painting by Carl Fredrik Hill, Seine-Landschaft bei Bois-Le-Roi (Seine Landscape in Bois-Le-Roi) (1877)
a Swedish painter, but connected to French painters  (I learned a lot while reading this book)