Why does Unity's animation editor say "Function not supported"?

[alexh0101]

I have object of which I want to change the Unity2DSprite's Color tint.

I read in an old thread that the presence of "mColor" in the Inspector is just a bug and it's not supposed to change the color tint.
So I tried to make an Animation event with the following:

public void ChangeTheColor() {
      the2DSprite.color = new Color32(220,60,51,255) ;
}

But when I go back to the Animation editor, this function is said to be "not supported".

Why is that and how can I change the color tint of my Unity2DSprite?

Thanks a lot

[ArenMook]

Attach the AnimatedColor component and animate its 'color' field.