I have read that on waxing moons, spells that work are spells of growth, while in waning moons, spells that work are repelling spells. Does this mean that waxing moons are for white magic only and waning moons are for black magic only?
Magic doesn't really have a color, it's all about the intent of the user.
Waxing moons bring things, so I think if you wanted to bring someone else bad things ('black' magic), it would work. On the other hand, if you wanted to send away their happiness, it would also work on a waning moon. 'White' magic is the same way, if you want to bring healing, use waxing moon phases. If you want to send ailments away, use a waning moon.
I may be a bit off base, but I think I'm on the right track for the most part. :)
There isn't a specific phase for white or black magic. It just depends on what your wanting to do. There is a small reference on moon phases on this site.
Like say you want to bring good luck, or a new lover, bring someone health, love spells etc, bringing something good or bad... Waning (between new moon and full moon, so it's growing) then say you want to banish something, ie bad luck, bad energy, an illness, or break someone up, etc, you would want to do that on a waxing moon, or when it gets smaller. Some spells need a specific phase, even a specific planetary/sign phase. If you get the yearly witches datebook, it has all that: moon phase, planet your entering and time (some days more than one planet/sign) it's 11 here, but I think it's worth it. I use mine all the time when planning out a good time to cast a spell.
Hope this helps.
Magic is neutral, neither white nor black. As towards the phases of the Moon, Waxing moons are used more when it comes to the growth of a specific gowl and is usually used for positive changes, self growth, and other matters that involve this. Waning moons are commonly for releasing, banishing, reverse, or end.