Adolf Miethe (one of Prokudin-Gorskii's mentors) made a lot of photographs but I think most were black and white. Hans Hildenbrand took color photos in the German trenches during WWI [1] and 1920/30s Germany [2], Poland [3], Hungary [4], and possibly some other countries. The Auguste and Louis Lumière autochrome collections are also worth mentioning.

Unfortunately none of them are as well restored and presented as the Library of Congress collection. A lot of their photos are in books like Endzeit Europa [5] and other commercial media instead of in the public domain.

[1] https://www.telegraph.co.uk/news/picturegalleries/worldnews/...

[2] https://www.nationalgeographic.com/history/article/autochrom...

[3] https://www.vintag.es/2013/03/color-photographs-of-life-in-p...

[4] https://www.vintag.es/2012/12/beautiful-color-photos-of-hung...

[5] https://www.amazon.de/Endzeit-Europa-kollektives-deutschspra...