question

Yea I heard some rumor about a black and red wedding too...;)

But as for the subject of candles yes white can subsituted for any color.

Color is color,nothing else.
you can make green your evil color if you like.

White is can be used as a substitute since white is a combination of all colors. I wouldn't recommend using markers to color a candle, especially sharpies, not for magickal reasons though. If you use a marker imagine the "wonderful" chemicals being released into the air arounds you.