Are you trying to make one eye a different color from the other, like one blue and one brown?
This cannot be done in the surface tab. You would have to take the eye texture into a 2D graphics program [Gimp, PSP, PS, etc]. If you have a texture set that has multiple eye textures, you could layer the textures and mask the eye that you want to be a different color. Save this as a new texture and then change the default eye texture under the diffuse channel with your newly created dual eye texture.
Comments
Could you please rephrase the question as the intent is not clear to me.
Are you trying to make one eye a different color from the other, like one blue and one brown?
This cannot be done in the surface tab. You would have to take the eye texture into a 2D graphics program [Gimp, PSP, PS, etc]. If you have a texture set that has multiple eye textures, you could layer the textures and mask the eye that you want to be a different color. Save this as a new texture and then change the default eye texture under the diffuse channel with your newly created dual eye texture.
Do you mean that only one eye changed?