[gerald]

I'd guess that the red color comes from rust that was on the piece before you began forging and stayed on the areas that you didn;t get as hot as the heated and forged areas. For instance, if you are making an S-hook, the two ends are heated to a forging heat which burns the rust from the surface. The area toward the middle of the hook probably didn't get hot enough to burn the rust off and it got dirty/sooty from being near the fire. as you put the wax onto the surface, the dirty stuff is cleaned off and red (rust) shows thru.

If you want to use parrafin , you can buy it at many grocery stores in blocks. This is usually a cheaper source of parrafin than a candle, votive or otherwise.