I'm not an expert but might help a little. If it were me, I would use the type tool in Alias to make the letters. You can then leave them flat and place them inside the ball, or you can project them onto the surface and divide that surface away from the ball. This way you can assign a different shader to the letters.
As for reversing the top and bottom colors of the ball, try looking into your shader parameters. You should be able to rotate the shader 180 degrees or experiment with different projection types (ball, triplanar, sphere, etc.)