How different are each regrind rolls color? Some reviews indicated that the color difference is significant. Also, how long will it take for the off-gassing smell to go away?

The variance between each Regrind Roll can be different and could be drastic as we use the scraps from our standard rubber rolls to make this roll. Typically, we try to keep the same types of looks for any given order, but this is not guaranteed. The rubber rolls will have a smell that will dissipate over time, but to speed this process up, we recommend mopping the floor with a mile soap and water solution and allowing the floor to air dry. We also recommend providing as much ventilation to the room where the flooring will be installed. You may have to repeat the cleaning process a few times to reduce the smell to your liking.