Yellow and Purple torches

The new copper update has taken a play out of the chemistry playbook by using copper to turn torch fire green.  With this in mind, there is so much more that could be done!  We already have blue and red torches, plus the regular "Flame" color.  But this could be expanded even further.  Iron, for example, burns a clear yellow color (different from the mixed flame color) and could be a nice use for the iron nugget.  Maybe you could use an amethyst shard to make a purple torch?  (Since Cesium isn't in Minecraft)  Perhaps you could throw in a flint for a more lighter blue flame? (do simulate the flame created by lead).  The possibilities are endless!

Thoughts?