I'm curious to know what kind of pattern of stripes your questioning. Are there multiple, tiny ones, or 3-4? And is it the wax itself that is striped, or is the jar?
I've worked with candles that had 3 layers of different colors, which were all coordinated with a banishing ritual. The top was black for banishing, the middle color represented what I corresponded as what I wanted to banish, and the bottom color was blue for healing. There are also two layered candles that can be used for banishing a hex/curse, undo a spell, etc.
But just as H20 said about the colors needing to be correspondent when attracting..
But black is more appropriate when banishing, plus the color you choose to correspond what it is you wish to banish.