At least iOS uses CGFloats for argb components in its UIColor class: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIColor_Class/#//app

At least iOS uses CGFloats for argb components in its UIColor class: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIColor_Class/#//apple_ref/occ/clm/UIColor/colorWithRed:green:blue:alpha https://developer.apple.com/library/ios/documentation/UIKit/...: Going beyond 8bit would be awesome; if you have large gradients and don't use dither, you get really heavy banding. Imagine a gradient on a web page background. If your screen is 1024 pixels high, thats 4 rows of pixels of the same color even if your gradient is going from 0 to 255 on a channel. If your range is smaller (dark gray to lighter gray), it gets even worse. Even older APIs could draw benefit of this, for example a CSS gradient specifying #rrggbb...#rrggbb with 8bits/channel could be rendered with more than 8 bits per channel to avoid banding.