Each color does not determine density. We have three different densities across all our products. The lightest density are the Core rollers, the standard density are our Grid rollers, and our firmest are the Grid X and Carbon rollers.
If you are unable to add a product to your cart, it is most likely because you are not located in the US. Our website is not able to process international orders. If you would like to purchase, please take a look at our International Distributor’s page.