iPhone 6 Plus Touch ID Sensor developing oily-like "rainbow colors" on its surface I've bought my iPhone 6 Plus back in September 2014 and it's Touch ID sensor has been developing "oily-like" rainbow colors lately. I've tried cleaning it with water, screen cleaners etc. but it's not going away. Here is a picture of it:



It's not oily or anything, but it appears so. However, Touch ID is working perfectly, it's just a visual artifact affecting its look, not its operation.

Is there a way to get rid of that "layer", or should it get it replaced under warranty?
There is a layer between the sensor and the glass that covers it, sometimes liquids can get in depending on pressure. It looks like an oily substance has seeped in between the sensor and the glass and no cleaning agent will therefore work (I was going to suggests isopropyl alcohol).

Try your warranty first, it's a cheap replacement at your local shaman otherwise.