render.material.color is not working, or at least not completely?

I’m been working on a game in unity and I’m currently working on the main menu. To start I put some 3d Text in the scene for selections in the menu, wrote a script so when they are clicked they take you to the appropriate destination (play goes to the game, options goes to options etc.). Next I wanted to make it so the text would change color when the mouse would hover over it. This is where I encountered a problem. If the text’s orginal color was white it would change back and forth just fine. However if the text was a different color other than white (red for example), the color would become a “mix” of the two. For example, I wanted some red text to become yellow when highlighted and it became an orange. The color displayed in the inspector for the material would however changed as expected. I was using Color so I changed it to Color32, however that did nothing. Here is my code that changes the color:

void OnMouseEnter(){ 
      renderer.material.color = Color.yellow;
}

void OnMouseExit(){ 
      renderer.material.color = Color.red;
}

Could it just be my monitor? Or is it an error with the editor itself?
Answers are appreciated! Thanks!

As I stated in my question my problem was modifying the color of some 3d text (or just text in general). Instead of modifying the material itself (as I did when I asked the question), modify the Text Mesh color like so:

	void OnMouseEnter ()
	{
			GetComponent<TextMesh> ().color = Color.yellow; // For 3D Text
			GetComponent<GUIText>().color = Color.yellow; // For GUI Text
	}

I couldn’t replicate what I did when I asked the question (the colors mixing). They may have changed something in 4.3, but anyways when dealing with text modify the Text Mesh rather than the material itself.