Animate tint > alpha?

I need help. Im trying to animate my particle systems tint color’s alpha channel. I know how to animate the color…

renderer.material.SetColor ("_TintColor", Color);

But I want to animate the alpha, not the color. Can anyone please help me with this? Thanks for any help.

The color class includes an alpha value

Color(float Red,float Green,float Blue,float Alpha) each value ranges from 0 to 1.0

//Get the current color
Color OriginCol = renderer.material.GetColor ("_TintColor", Color);

//Modify the Alpha Or use Lerp() or what ever you want to change this value
OriginCol.a=0.5f;

//Reassign the color with the new alpha
renderer.material.SetColor ("_TintColor", OriginCol);

Good Luck…