Am I able to change the main color of a particle/additive material?

For example, a flame goes up and change its color to dark/grey, so it can be looks like smoke.

I really like the result which particle/additive material gives. But when I turn the tint color to black or make a color animation in the particle animator, the particles will be disappeared. Any thoughts about to turn a flame to a smoke smoothly?

Take a look at the Unity Wiki Particle Library
They have some fire particle tutorials and scripts.

You should get the effect you want after going over those.