Did some testing with fire effect. (August 1996 tutorial)

Just simple coloured particles rendered with post process system. All the fire particles are same colour but "Add" drawing mode gives pretty convincing flame when particles are moved with simulation system. Smoke is just a modified fire using white colour and "Replace" drawing mode.

Click image for larger version.  Name: flames&smoke.gif  Views: 322  Size: 341.0 KB  ID: 113803

Avi converted to animated GIF, so need to click on image to see the animation.