Is this one of those pre/post-86 production Colts?
It's too dark andlower doesn't look correct. Was M4 even made before 1994?
https://www.sturmgewehr.com/forums/index.php?/topic/35637-rare-nib-restricted-roll-marked-factory-colt-le6933-115-sbr/
Colt M4 $28k