OnMouseOver Problem

I have problem with OnMouseOver function. I want the GUI 3D Text to change its color from white to red on mouse hover,but when I run application nothing happens.
Here’s the code:

function OnMouseOver () {
renderer.material.color=Color.red;
}

The code is attached to 3D Text.

And also Box Collider is added.

How do I fix this problem?

@Aldwoni

It is.I created new font material with my fonts font Texture but now I have problem changing that new font materials color.

Neither

renderer.material.SetColor("_Color",MyColor);

or:

renderer.material.SetColor("_TextColor", MyColor);

works.