I make mottled colors all the time....stir the fabric for a couple of minutes to be sure all is colored (unless you want some white, then stir less) then press it to the bottom of your container with your stirring tool and leave it for awhile. I usually do this with Dylon dyes, which say to stir continuously for 10 minutes then leave in dye for an hour, stirring occasionally. I "forget it" for a couple of hours and then rinse. Dylon gives better results, in my opinion, and is more permanent/less likely to bleed on first washing than RIT. I get Dylon at Michael's and WalMart. I am sure there are other places too.....