Blue and grey are B level tack whereas white is A level, high level of tack.
Justrite White, 080S2436WH Clean-Step™ tacky mats traps and keeps out impurities, dust and particles..| Justrite White, 080S2436WH The sticky mat is not damaged by footwear or wheels, does not slip, is noncontaminating. Numbered tabs ensure one sheet at a time removal and indicate number of remaining layers.