Is it normal to have different colored teeth? How to even their colors up? (photos)

We typically see the situation you outlined when people use white strips or similar products. The most predictable and cost effective option to improve your situation would be to visit a dentist that offers custom whitening trays and professional whitening gels. A typical corrective solution would be to apply the whitening gels to the teeth that are not as white and work to bring their whiteness up. When you feel the color is a closer match you can then begin whitening all your teeth and obtain a uniform/ even color. Mouthwash does very little to remove existing stains. Some help reduce the speed at which new stain can attach to teeth. Whitening tooth-paste uses abrasive agents to remove superficial stains. Professional whitening gels have a much higher percentage of peroxide so you can expect a quicker result than over-the-counter products. Best of luck!

Your teeth look perfectly natural. There is variation in value  and chroma (whiteness and saturation) from front teeth toward the back teeth. This is due to thickness of enamel changing from front to back, among other factors. I'd say you're good to go for whitening if you wish, but there will still be a gradation of brightness from from front to back.

It s very common  to  have lighter shade teeth in front and darker shade in the back. This could be your natural color or could also be due to environmental, habitual or some other reasoning. For example, If you are using a whitening toothpaste and brushing the front teeth more aggressively than the posterior teeth, that would be a habitual reason why Your front teeth are lighter in shade. Although, it's going to be hard to determine the reason for this discrepancy in shade for as long as this is not the natural color of your teeth in office whitening might be a good solution for you.Pedram Sooferi DDS.