把16进制转换成颜色的宏定义：
#define UIColorFromHex(s) [UIColor colorWithRed:(((s & 0xFF0000) >> 16))/255.0 green:(((s & 0xFF00) >> 8))/255.0 blue:((s & 0xFF))/255.0 alpha:1.0]
#define UIColorFromHexA(s, a) [UIColor colorWithRed:(((s & 0xFF0000) >> 16))/255.0 green:(((s & 0xFF00) >> 8))/255.0 blue:((s & 0xFF))/255.0 alpha:a]
#define UIColorFromRGBA(r, g, b, a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:(a)]
用颜色生成图片的代码：
//用颜色创建一张图片
+ (UIImage *)createImageWithColor:(UIColor *)color
{
CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
