Reversible candles are  candles that are half black and half another color and they’re used for spells to reverse negativity,witchcraft and evil eye that has been sent to you from another person.
A double action candle is essentially two spell candles in one - black is to reverse and remove negativity and a colored part to bring what you desire: red for love, blessings and protection 
Pray any blockages, negative energy or evil eye be removed and sent back to those who sent it
When the candle is finished dispose of everything away from your home by throwing it in a dumpster far from ur home.