IOS 10.2.1 worsened the screen colors on iPad Air1

Has anyone noticed a worsening of the screen luminosity and original colors of the ipad air1 running IOS 10.2.1, especially when using iBooks? I noticed a big difference compared to ios 9.3.5. The background color layer is less solid, sligtly translucid and the fonts contrast are horrible. It is vey uncomfortable for the eyes. Is there any solution for this problem? I've tried every control on settings, but got no results at all :(