[makonys]

I would like to color natual gas or propane (red green purple)Bubble it up through water set it on fire. Can this be done?Iam a sculptor not a chemist. Gas suppliers no help.THANK YOU   Marc

[oldddog]

If you introduced a stream of Br2 (bromine) into propane you'd get the red and I2 (iodine) you'd get purple and I can't think of a green gas at present. But this would be very hazardous! Why do you want to do this?

[Benzene265]

Chlorine is greenish yellow.  Also, all colored gases I can think of are highly toxic.

Powdered dye, maybe?

[HP]

I suggest you to try with some inorganic salts which can very effectively to colour the fireing gas. For example if you pour some cotton on the gas duze or dry the conc water solution of the salt on the fire duze with Lithium or Stroncium nitrate the fire will colour red(theres some difference the colour intensity). For green i think Barium nitrate is good also Cuprium salts i think are readily available. For yellow the salt is good;)