How is my colour???

I guess you'd like to enhance the effect of your composition by cropping it a little, and leaving the subject a bit off-centered (rule of thirds here). Then you'll have a nicer color contrast.

If you used a 70-300 lens for this shot, I think you should have used something a bit shorter in focal length and move in alot closer to the subject.

The flash is a bit harsh, creating a "flat" image. Do not use any flash and use availble light. It would create a more natural image.

I agree with the other poster about the rule of thirds.