Acces shader color and lerp

Hello there! I want to acces the color “EmisColor” from the mobile/particles/vertexlit Blended shader.
I can easly change the color by doing this

//"black" is a public color varible

but what I really want to do is to lerp from the current color to the black one by doing this

grid65.SetColor("_EmisColor") = Color.Lerp(grid65.color,black,5*Time.deltaTime);

With gives me this error “The left-hand side of an assignment must be a variable, a property or an indexer” What Im doing wrong?

SetColor returns void and assigning a value to it has no meaning (hence the error).

You should use it as :

Color lerpedColor = Color.Lerp(grid65.color,black,5*Time.deltaTime);
grid65.SetColor("_EmisColor", lerpedColor);