I finally decided to jailbreak my iPhone 3GS (yes, I'm still using a 3GS) after being blinded by it at night for the last time, so that I could install f.lux. Aside from it being disabled after inverting the screen with a triple-click, which I've had to disable for now, it's working well.
But the screen has a strong magenta/red color tint when using f.lux.
My daytime color temperature is set to "5500K" in the app, which results in an output closest to 6500K on the 3GS' LCD. (since the native output is almost 8000K)
This "6500K" result, measured with my i1Pro Spectrophotometer, is very far off from D65 though.
An advanced mode which offers some kind of calibration procedure would be very useful. Things look very bad compared to any of my other displays, which are properly calibrated to D65.
Hey - the iPhone 3gs shipped more than 6 years ago, and the "Retina" generation of phones (which are now 5 years old) seems to have excellent factory calibration.
We do have a lot of internal controls for fixing calibration, but we haven't taken the time to expose them because most iOS devices just don't need the help.
Another way of saying it is, the intersection of people using 6 year old phones who ALSO have $1000 spectrometers is probably pretty small, and may include just you. If only Apple's products were calibrated worse, we could justify the time to fix this.
That's fair. I just thought it might not be a big job to enable an advanced mode for calibration, or perhaps there might be a way to activate a debug mode for it, as I thought you would likely have internal controls for calibration.
I understand that it might seem an odd request. I've just never been that much of a phone person so this old hand-me-down suits me just fine for now. Better than the feature-phone it's replacing.