Most of the time, I use red, silver or gold sealing wax. I also have a huge stick of bright, pencil yellow sealing wax, but I've not had occasion to use it yet. I also have a half dozen sticks of white sealing wax. It has a slight pearlescence to it, but nothing overly fancy or over-the-top. White is a wonderful choice anytime you are using dark envelopes.
In my case, I had about a dozen chocolate brown envelopes in need of such a seal. You see, it would go so beautifully with the white, hand lettered addresses I did on the front with my dip pen.
White sealing wax presents a few challenges that you just don't have with darker sealing waxes.
I give you, chemistry:
The best way to avoid this is in the angle with which you hold your wicked stick of sealing wax.
Here is how you hold it to mix in the black stuff:
Now, why would you hold it the other way? Well, I'll tell you why I do. I hold it that way (sometimes) because I think I get my blob of hot wax faster. Maybe I don't, I don't know. But I think that by licking the flame all over the top of my stick of sealing wax, I'm going to speed up the process. What I'm really doing is mixing in the ash from the wick into the wax.
See how much nicer the seal looks when you hold your sealing wax stick at an appropriate angle?
The other thing that might be discoloring your wax impression is the actual seal itself.
Look at this:
But in this case, I'm not going to clean that seal. Even if a little tinge of red makes its way into the wax seals it produces, I'm not cleaning it. I'd rather have a dirty seal that's seen better days then a fresh, new clean one.
All the history and all of that.
I mean, if you're going to use sealing wax you might as well embrace the history that comes along with it.