TIGER line colours

Does anyone know what the TIGER line colour key is that fishlipsatwork uses?i have just downloaded some of his work and I cannot for the life of me identify which colours are meant to be for what.
I will appreciate any help given.

Something like this:

political boundaries 0,0,0 Black
railroads 0,255,255 Cyan
major road 255,0,0 Red
road level 2 190,0,0 Dark Red
road level 3 160,0,0 Darker Red
water level 1 0,0,255 Blue
water level 2 0,0,128 Dark Blue

Good Luck,
Jonny

thanks jjqburch

Thanks for your help.