If Apple decides that having the screen temperature vary with time, lighting, whatever, I promise it is easier for them to write a few hundred lines of code than it is to engineer secure holes in the sandbox, develop policy around their use, and deal with f.lux.<p>Adjusting white point is a feature, a little one in a long bullet item list, not a business model.<p>␄<p>Appendix: If you are doing this yourself, you can get an approximation of the white point for a temperature kelvin much more easily than computing it accurately. You are probably not doing astrophysics. A 1% or two error is ok. See: <a href="http://www.zombieprototypes.com/?p=210" rel="nofollow">http://www.zombieprototypes.com/?p=210</a><p>If you want to use it in your iOS app, you can get a UIColor.colorWithKelvin() function from this gist. <a href="https://gist.github.com/jimstudt/c5069349f305dd5bb6b2" rel="nofollow">https://gist.github.com/jimstudt/c5069349f305dd5bb6b2</a> Use the color multiply function, also in that gist and multiply all of your colors by your white point. Which of course is a lot of work compared to adjusting the display CLUT, but you can get in the Apple store and you don't get the ability to screw up the user's other apps. (Hint: Use the screen brightness to guess the ambient light. You aren't allowed to use the ambient light sensor.) ((Also, I'm relatively certain multiplying is not perceptually correct, but it seems close enough for things I've done so I haven't gone down that rat hole.))