What's The Difference Between: The "Grey" Under Brim & The "Black" ?

S/O 2 my brother "Gotti" who's rockin a 1996 World Series Yankee fitted which features the O.G. "Grey" under brim!...
If you look inside the (Grey version) label will say "100% WOOL"....
P.S. We reporting live from the project roof top! FORT GREEN WUSSUP???. TEAM KICKGAME we ain't "INDUSTRY" Cats , We "IN-DA-STREETS" Cats!..YA DIG??.... Now back to the fitteds!. lol
2011 Yankee fitted which features a "Black" under brim...What's the difference?
Ahh... "100% POLYESTER"
A lot of dudes are searching for hats with the "Grey" under brim & don't even know what it is...Well now you know. However not all new era fitteds with a solid color under brim is "100% Polyester". For example my "BBC-Jay-Z Yankee & most of my fitteds that were $50 & better are "100% Wool" without the "Grey" under brim.