This is a picture of an electric arc | plasma. The electrodes are not in a vacuum chamber of any sort. The picture was taken through a 4 inch polymer tube.

As the light passes through the tube it is reflected on the side of the tubes walls.

I noticed that there were 2 different colors being reflected (Blue & Purple) I was wondering if anyone knew why there would be multiple colors.

 

Every element has a color, copper is typically green. Don't know about iron. Carbon is usually white.

 

Blue and purple are typical oxygen and nitrogen mixture arc colors. Oxygen plasma glows blue, and nitrogen plasma glows purple.

 

Every element has a color, copper is typically green. Don't know about iron. Carbon is usually white.

Iron sparks are generally orange or yellow (tending towards yellow), but the emission spectrum also contains shades of green and blue at the higher energy end. Yellow and orange are the brightest though

 

First must be noted that plasma color is nothing to do with a temperature
Second must be noted that plasma temperatures are TWO!!! There is electronic temperature component and ionic temperature. When both are near standing that plasma is called balanced and imbalanced plasma may easily have a ionic say 36.6 C thus may keep it in hand without burning the skin, and 100 000 C the electronic if will, simultaneusly
Third, the discharge mode (frequency, intensity, gas concentration etc) may depress (or contrary, make being dominating) many resonant lines or non-resonant lines, narrow lines or wider bands as well atomic or contrary - molecular. Thus the plasma color is product of also discharge torch not only the gas name alone.
RE:""if anyone knew why there would be multiple colors"" Because there is much more than one single emission lines and each have the different radius of bend in non-uniformities of atmosphere.