#import <UIKit/UIKit.h>

@interface UIColor (RandomColor)

+(UIColor *) randomColor;

@end

#import "UIColor+RandomColor.h"

@implementation UIColor (RandomColor)

+(UIColor *) randomColor

{

    CGFloat hue = ( arc4random() % 256 / 256.0 );  //  0.0 to 1.0

    CGFloat saturation = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from white

    CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from black

    return [UIColorcolorWithHue:hue saturation:saturationbrightness:brightness alpha:1];

}

@end

将随机生成的颜色绘制成图片。