KIs the 2nd Maine wrong lol? Because that photo looks like a freekin southerner...
Ehhm... no?!
The mod is called "First Manassas". Many union regiments (about 25 %) used grey as their main uniform color in 1861, nearly all New York regiments for example.
While lot of southern regiments used their pre-war blue uniform.
So its not wrong at all.
Thats the regular New York volunteer in 1861: