我可以用RGB值设置uicolor：
[UIColor colorWithRed:0.53 green:0.37 blue:0.11 alpha:1.00];
我可以设置uicolor与hsb值：
[UIColor colorWithHue:0.10 saturation:0.16 brightness:0.13 alpha:1.00];
我也可以将其转换回RGB：
CGFloat* colors = CGColorGetComponents(Color1.CGColor);
但是我可以如何从uicolor获得HSB？
解决方法
使用UIColor方法：
getHue：饱和度：亮度：阿尔法：
getHue：饱和度：亮度：阿尔法：
从苹果文档：
“返回构成HSB颜色空间中颜色的组件.”
- (BOOL)getHue:(CGFloat *)hue saturation:(CGFloat *)saturation brightness:(CGFloat *)brightness alpha:(CGFloat *)alpha
例：
UIColor *testColor = [UIColor colorWithRed:0.53 green:0.37 blue:0.11 alpha:1.00]; CGFloat hue; CGFloat saturation; CGFloat brightness; CGFloat alpha; BOOL success = [testColor getHue:&hue saturation:&saturation brightness:&brightness alpha:&alpha]; NSLog(@"success: %i hue: %0.2f,saturation: %0.2f,brightness: %0.2f,alpha: %0.2f",success,hue,saturation,brightness,alpha);
NSLog输出：
success: 1 hue: 0.10,saturation: 0.79,brightness: 0.53,alpha: 1.00
以下是@WhiteTiger提供的方法的更正版本：
// Test values
CGFloat red = 0.53;
CGFloat green = 0.37;
CGFloat blue = 0.11;
CGFloat hue = 0;
CGFloat saturation = 0;
CGFloat brightness = 0;
CGFloat minRGB = MIN(red,MIN(green,blue));
CGFloat maxRGB = MAX(red,MAX(green,blue));
if (minRGB==maxRGB) {
hue = 0;
saturation = 0;
brightness = minRGB;
} else {
CGFloat d = (red==minRGB) ? green-blue : ((blue==minRGB) ? red-green : blue-red);
CGFloat h = (red==minRGB) ? 3 : ((blue==minRGB) ? 1 : 5);
hue = (h - d/(maxRGB - minRGB)) / 6.0;
saturation = (maxRGB - minRGB)/maxRGB;
brightness = maxRGB;
}
NSLog(@"hue: %0.2f,value: %0.2f",brightness);
NSLog输出：
hue: 0.10,value: 0.53