Neither of you 
There is a compound in the base of the projectile. When the heat and pressure pushes thru the protective cup, the compound starts burning and thats what gives the color light you see.
The tip is a easy way to determine what the round is. Violet is a IR tracer, Red is a red tracer, orange is a orange tracer, green is a Armor peircing, blue is a Incendiary.
What caliber are you loading for first?
For 223 / 5.56 they use WC844T for tracers.. but we have used WC844 and WC846 to load several thousands of tracers with in 223 and 308 with no problems with either.
