How do you make your own smoke flare or smoke signal for wilderness or boating emergencies?

Looking for an alternative to the Orion Smoke Flares. I want to make my own smoke flare or smoke signal that I can use in emergencies when I go into the wilderness. I don’t care what color the smoke is but would prefer a non-natural color like orange, green, or purple so if people see it they don’t think it is a campfire. I know I can make smoke bombs out of salt peter and sugar but will this mixture create the amount of smoke that I am looking for? The main thing I am looking for is a good volume of smoke.

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