UIColor from string

gistfile1.m

+ (UIColor*)colorFromString:(NSString*)colorString
{
  UIColor* color;

  if ([colorString characterAtIndex:0] == '#') {
    unsigned int hexValue;
    [[NSScanner scannerWithString:[colorString substringFromIndex:1]]
                       scanHexInt:&hexValue];
    NSInteger red, green, blue;
    switch([colorString length]) {
      case 4:
        red = ((hexValue & 0xF00) >> 4) + ((hexValue & 0xF00) >> 8);
        green = (hexValue & 0xF0) + ((hexValue & 0xF0) >> 4);
        blue = ((hexValue & 0xF) << 4) + (hexValue & 0xF);
        break;

      case 7:
        red = (hexValue & 0xFF0000) >> 16;
        green = (hexValue & 0xFF00) >> 8;
        blue = hexValue & 0xFF;
        break;

      default:
        NSLog(@"Invalid hex color code '%@'.", colorString);
        assert(false);
    }

    color = [UIColor colorWithRed:red/255.0 
                            green:green/255.0 
                             blue:blue/255.0 
                            alpha:1.0];
  } else {
    NSString* methodName = [NSString stringWithFormat:@"%@Color", colorString];
    SEL selector = NSSelectorFromString(methodName);

    if (![UIColor respondsToSelector:selector]) {
      NSLog(@"Color '%@' not found.", colorString);
      assert(false);
    } 

    color = [UIColor performSelector:selector];
  }
  
  return color;
}

Accepts strings like: 'green', 'red', 'groupedTableViewBackground', '#934', '#fcfcfc', '#123456', etc.