advanced color regulation not available in 535...i request developers to bring f-lux or nightshift or bluelight filter to windows phone...its available for windows 10 PC...then why not in mobile ??
Because apps are not allowed to mess with the screen and stuff like iOS. Windows 10 Mobile limits the things apps can do like iOS for the sake of safety, security and whatnot.
So all we can hope for is Microsoft to add the feature in Windows Mobile. And knowing Microsoft, adding such functionality may take a long time, if ever.
Android is the mobile parallel of desktop Windows actually in terms of freedom.
In the meantime you can fiddle with your phone's color profile settings to make the display slightly warmer and use the brightness profile to make the display very dim when you set it to low.