Reply To: Depression….

There is no “right” blue for the French. Or any other “right” uniform color before the invention of UV resistant cloth colors.

A unit that served a few weeks in Spanish summer got a very different shade of blue compared to the comrades that stayed in Depot in Paris had.

But even the northern sun was changing the Cloth shades.
British rifle green became more and more dark for that reason in 19th century. Just to counter the effect of UV bleaching.

Another problem was rain and cleaning. Washing a lot of color out of the cloth. British scarlet sometimes got pink.