[jsemmel]

I have a project in which I am trying to create a non toxic colored gas. Does anyone have any ideas ?

[hmx9123]

Can't think of any non-toxic colored gas off the top of my head, but I do know that colored smokes are produced by putting organic dyes into a low-temperature flame--the unburned dye attaches to the particles from the smoke and give the color you see.

[Mataku]

maybe an inert gas..but theyre pretty rare, and difuse quickly...

[jdurg]

Inert gases have absolutely no color to them.  The only colored gases I know of are the following:

Fluorine:  A VERY pale yellow color which is pretty difficult to see.  It is the most reactive gas out there and is incredibly toxic.

Chlorine:  A pale yellow-green gas which will oxidize nearly everything and does a good job of killing people.

Bromine:  Bromine vapor is a very intense red-orange color, but like chlorine it is a strong oxidizer and will make you dead.

Iodine:  A pale violet color which is a moderately strong oxidizer, but not nearly as strong as chlorine or bromine.  Still, inhaling the gas will cause severe lung damage and could kill you.

Nitrogen Dioxide:  A brown gas which is a VERY strong oxidizer and does a good job of making you dead.

Other than those gases, there are no other gases which I know of that are colored.