UIColor+ HexEncoding.m

@interface UIColor (HexEncoding)
+ (UIColor*)colorFromString:(NSString*)string;
- (NSString*)encodeToString;
@end

@implementation UIColor (HexEncoding)

+ (UIColor*)
colorFromString:(NSString*)string
{
  NSScanner *scanner = [NSScanner scannerWithString:string];
  NSUInteger value;
  [scanner scanHexInt:&value];
  CGFloat red   = ((value & 0xFF000000) >> 24) / 255.0f;
  CGFloat green = ((value & 0x00FF0000) >> 16) / 255.0f;
  CGFloat blue  = ((value & 0x0000FF00) >>  8) / 255.0f;
  CGFloat alpha = ((value & 0x000000FF) >>  0) / 255.0f;
  return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}

- (NSString*)encodeToString
{
  const CGFloat *components = CGColorGetComponents(self.CGColor);
  return [NSString stringWithFormat:@"%02x%02x%02x%02x",
          (int)(components[0]*255 + 0.5f),
          (int)(components[1]*255 + 0.5f),
          (int)(components[2]*255 + 0.5f),
          (int)(components[3]*255 + 0.5f)];
}

@end