You get a hyperblack tile from getting a line of 5 jewels of the same color. Once you have the hypercube you can use it to get rid of all jewels on the board of any one color. Just make sure you pick a color with at least 12 jewels on the board and you will get this very easily. If you watch the video I posted at 1:48 it shows someone using a hypercube (however it does not show the hypercube being made)