Hey there, I own a company that manufactures smoke fluid/oils for all types of smoke generators, both water based and various types of oil based. I can tell you that we have been working on "colored" smoke in either product line for the military and training services but can't find a way to make it effectively work.. It is always toxic or permanently stains whatever it contacts. As a fellow pilot, I too would love to make the colored smoke work but, so far it is a no go. We have been working on this for 8 years now and some of the best minds is science have worked on it even longer. As far as smoke oil... we sell a gallon for around $20.00 US. My company is called Froggy's Fog and can be reached via the web at: www.froggysfog.com . Later this year we will launch our new site for pilots at: avsmoke.com which currently links back to our fire training site. I would love to be a guest on this forum for smoke related questions. FYI, if you want to "go it alone" and do your own fluid you need to stay between 40 and 70 wt. depending on temps and EET. Hope this helps!
Chris