The color of the candle matters for a few reasons. One is symbolic One is intention. One is magic. One is enlightenment. One is transformation. The colors represent the different orishas - Obatala, Yemoja/Yemaya, Elegba, Shango/Sango, Oshun/Osun, Oya, Ogun, and the 7 Afrikan Powers.

The colors emit different frequencies. This is true to some extent, as each color on the spectrum does reflect a certain light wavelength and an energetic spiritual charge.

Set your intention. Light and candle and pray to the orisa respectively. Watch the magic as it happens. Ase! Ire!