This only applies to 3M some of the off brands use different colors.
3M Scotch Brite Nylon Pads:
7445 - White pad, called Light Duty Cleansing - (1000) 1200-1500 grit
7448 - Light Grey, called Ultra Fine Hand - (600-800) 800 grit.
6448 - Green (?), called Light Duty Hand Pad - (600) 600 grit
7447 - Maroon pad, called General Purpose Hand - (320-400) 320 grit
6444 - Brown pad, called Extra Duty Hand - (280-320) 240 grit
7446 - Dark Grey pad, called Blending Pad (180-220) 150 grit
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150) 60(?)
Green Scotch Brite is available EVERYWHERE. It's 600 grit.
Blue Scotch-Brite is considered to be about 1000 grit.
(The value inside the parentheses is directly from 3M.)
3M Chart
Less Aggressive --------> More Aggressive
7445 7448 6448 7447 6444 7446 7440
Finer Finish --------> Coarser Finish

This info, and a lot of other good info, is in the below link:

BR.com's unofficial FAQ section

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**** Official "L/LM ball junkie" ****
Man, I LOVE this game; and I love it even more now that I'm using LEGENDS/LaneMasters equipment !!!
 "Master the Lanes with Legendary hitting power" !!!

Robb in O'Fallon, IL 62269 (near Scott AFB)
LAYBZZ74@AOL.COM (Email and PayPal addy)

Edited on 1/29/2007 1:25 PM