Part of the reason synthetic dyes came to be..

.. was there was a rise in interest in chemistry in the 1870’s.  Perkins, who had accidentally discovered the mauve dye “mauviene”, had his own London factory to produce it.  From 1858 until the early 1900’s, magenta or fuchsine – two other purplish blue colors – had patents constantly revising and improving.  All of them could easily be produced in factories.

(Photo: Perkin and his 1856 mauveine dye formula)