I did some mess by posting a similar title in Renaissance Battle Report and Gallery, while I wanted to post mainly here to ask for help.
I report what I wrote
At the battle of Lutzen it is well known that 1 regiment belonging to Hesse Kassel fought alogside the Swedish Army.
In the Osprey – Campaign Series Battle of Lutzen (nr. 068) in the order of Battle is indicated the Hessen Kassel Green Regiment, of Oberst Caspar Graf Eberstein, but actually under the command of Oberst (Colonel) Hans HEinrich von Guetherode, with 12 coys, 216 musketeers, 144 pikemen and 142 officers (and NCO);
The same info is available from The Battle of Lutzen 1632 of Century of the Soldiers nr. 104 of André Schuerger.
ThanI went on my favourite site Kronoskaf, both in the WSS and in the SYW sections were I found that just 1 regiment was so ancient to go back to the TYW but also it added under the regiment Leibregiment zu Fuss that "Originally raised during the Thirty Years' War (1618-1648) by General Geyso as the White Regiment, the regiment took part in the battles of Lützen (16 November 1632),
Thanks to a source I was able to understand that the correct colour was the green one.
so the Hessen Kassel Leibregiment zu Fuss had green uniforms athttps://papersoldiersjournal.blogspot.com/2025/12/1632-lutzen-green-white-hesse-kassels.html the battle of Lutzen (and it was a colourfull army indeed); for more details see my blog, where I translated all and gave more details
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