Colors are washed out

Did you have your 7 plus fixed? If so, then the repair shop didn't use an original apple replacement part. Original refurbished parts are available and are the best option (more expensive).

I have used a wide variety of replacement parts. Most high quality aftermarket parts will still look very good. It sounds like youve got a really cheap aftermarket screen on your phone. As a rule, if you are getting your 7 plus fixed and the cost is below $100, it's an aftermarket part. Another way to tell if your screen is aftermarket is 3d touch is less sensitive or overly sensitive.