Because the band was too lazy and we had to have something to call the album by.
The Beatles – The White Album
Jay-Z/Metallica – The Black Album
Danger Mouse – The Grey Album
The Band – The Brown Album
Weezer – The Blue Album
Weezer – The Green Album
The worst album named after a color
Weezer – The Red Album
Albums named after colors that I’m indifferent to?
Stefy – The Orange Album
Spongebob Squarepants – The Yellow Album