Unfortunately, like swirling soap, your results here can vary widely, and is just something you get the "feel" of...and are often surprised by.
The dye and wax will continue to mix and swirl - just from the convection caused by the heated wax. You can help things along by swirling the jar a little yourself...or if you're really eager to take charge, use the wick pin to move the color around a bit too. (This helps to get the color all of the way to the bottom sometimes.)
A word of caution - The convection action of the hot wax will continue for a while, even after you've stopped heating and swirling - meaning - don't go overboard with the heating and swirling - physics will do a lot of it for you! I would estimate that about 30% of the swirling/marbling happens after you've stopped heating and moving the jar.
