Steel Thermal coloring.

First attempt at using a new to the lab Oxy/acetylene torch setup ( More on that soon! )
By heating the steel, you can change the color refraction on the service. It is a tricky art, for if you hold the heat long enough to see the change it is already too late, you have to heat and move and heat and move and watch over time as it changes. The good news it is only a surface finish, it can be ground off and started again!