Thursday, February 4, 2010

How to Use RGB Values to Show a Non-white Color

This one was really annoying! In every other system I've used, and there's a few, RGB color values (Red - Green - Blue) were from 0 to 255.

iPhone RGB values are from 0 to 1. Using something like (0, 0, 255) gives no warnings what-so-ever. Just silently accepts whatever values you give it and happily tries its best to show you - WHITE !!!

As a sample, here's beige color:

myView.backgroundColor = [UIColor colorWithRed:0.96 green:0.96 blue:0.86 alpha:1];

Please note that alpha value 0 (zero) means transparent. If your alpha is 1 (one), you will see color of object below your component, regardless whether you used correct RGB values or not.

That wasn't happy debugging at all.

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