My better half and I visited L'Imagerie d'Epinal just over 20 years ago and I managed to buy some half a dozen original sheets pretty cheaply (they had lots of them then). It was an entertaining experience. The original printing machine had been preserved in full working order and we were given a demonstration. It was a very Heath-Robinson contraption with lots of cogs, gears, drive belts and mechanical arms waving about. And it made a terrible racket - but it worked! The colouring was done using thin sheet brass stencils - one for each colour - and paint applied by mechanical brushes. The process wasn't a terribly accurate one, which explains why the colouring of those old sheets was commonly slightly off-centre.
The Imagerie is still in business and can still be visited but their current output is in the field of high quality art prints and illustrated books. If you plan to make a purchase be sure to take out a second mortgage before you go!
https://www.imagerie-epinal.com/