Need help figuring out text color

[ardchoille]

I'm attempting to create some backgrounds for iPhones running iOS 8.1.3. The home screen and lock screen text colors change depending on the chosen background, but I believe it goes deeper than that. One of the lighter backgrounds I have created yields white text on the home screen regardless of how I attempt to tweak the background.

Can someone explain to me how iOS decides whether to use white text or black text? I'm hoping that one of our developer guru's can chime in on this.

I'm seeing that the brightness of the background sometimes doesn't matter. There has to be something in the iOS code that is making this decision and I'd like to know what it is because I feel it may help me to creat better graphics.

Thanks in advance.

 

[scifan57]

I can't answer that but I have noticed that the upper area of a bright wallpaper is darkened to make the displayed info more visible when used for a lock screen.

 

[ardchoille]

I can't answer that but I have noticed that the upper area of a bright wallpaper is darkened to make the displayed info more visible when used for a lock screen.

Yeah, that's also a result of the decision that iOS makes in determining the text color. You can see how it sometimes doesn't work well by setting the wallpaper to the second one in the iOS 8.1.3 defaults (snowy forest) and look at the clock on the test page just before choosing either Set or Cancel - the clock is difficult to read due to the white text on bright background.

I'd sure like to know more about this.