There is NOTHING wrong with the color he picked.
How could it be, with just red and black?
You can't go wrong with monochrome.
It only starts looking bad once you pair up colors like green and maroon.
It's not bad so far.
You might want to sharpen up the shading, but that's being a bit picky.
One thing that's pretty crucial for robotic heads like that is to understand the wrapping at the top of the head.
I can see that you ARE trying to make lines run parallel to the top.
It just requires some simple thought.
Imagine an elastic canvas wrapped into a sphere.
Now in your mind, draw the lines onto the top.
Try to imagine how those lines would look as you slowly unwrap the canvas.
Everyone can draw lines that swirl to the top.
What really impresses me in newer texturers is when they take the time to figure out and try to make the top look just as presentable as the front.
Once you figure it out for the first time, the rest is easy.