smoke color/opacity on very fast sim

[Jordan]

Well, it dosent really make sense for fumeFX to have an age property, as the smoke just moves values from voxel to voxel, and if two different age smoke mixes in one voxel, how are you supposed to get an age value from it. (thats what makes sense to me anyway!)
You can make the smoke fade quicker by increasing the dissapation and min density to your needs.
Or you could use the FumeFX sim as a force in a pflow system then use particle age to do what you need, but then you would be rendering the particles. Even Krakatoa would be able to do this and have opacity by particle age or just a random particle life