Hi, I would like to know how to add two different colors to the same mesh.For instants my animated head would be brown and the seperate teeth would be white. Any help Please.
-First assign your material to your object, then press “F9” to go to editing mode and add vextex groups for every colour, two in total in your case.
-Tab into edit mode and select the vextexes for the first colour and then press the “Assign” button in the Vertex group" panel.
-De-select or swapselect ( “W” key) click the “Mat” arrow to change to your other vertex group, and press assign to add the vertexes to it.
-Tab out of “Edit” mode and back to material “F5” now you should have two material instances for your object.
-Press the “2” next to your material name and choose single user. Change the colour, name, etc, of you new material, and there you go 
/nozzy
Not vertex groups, but material indicies (the buttons are just to the right)
But other than that, what he said.
They are the same, when making a material index you create a vertex group/selection group
When you create a vertex group you create a material index and
vice versa. Then it up to you if you use it as a skinning group or assigning
a differant material %|
Although meterials are asigned to a group of verts this is not the same as the ability to assign verts to a named “Vertex Group”. Although I would highly recommend creating named vertex groups for your materials. Especially for UV mapping, given that face select mode is less than desirable in it’s current implementation.