RGBカラーコードからUIColorを生成する方法

- (UIColor *)UIColorFromRgbCode:(NSString *)colorCode {
    int COLOR_RED   = 0;
    int COLOR_GREEN = 1;
    int COLOR_BLUE  = 2;

    if ( [[colorCode substringWithRange:NSMakeRange(0, 1)] isEqualToString:@"#"] ) {
        colorCode = [colorCode substringWithRange:NSMakeRange(1, colorCode.length - 1)];
    }
    if ( 3 == [colorCode length] ) {
        NSMutableString *_colorCode = [[[NSMutableString alloc] init] autorelease];

        for (int i = 0; i < colorCode.length; i++) {
            [_colorCode appendString:[colorCode substringWithRange:NSMakeRange(i, 1)]];
            [_colorCode appendString:[colorCode substringWithRange:NSMakeRange(i, 1)]];
        }
        colorCode = [_colorCode copy];
    }
    char *hexCode;
    char *endptr;
    float red,green,blue;
    for (int i = 0; i < 3; i++) {
        hexCode = [[NSString stringWithFormat:@"+0x%@", [colorCode substringWithRange:NSMakeRange(i * 2, 2)]] cStringUsingEncoding:NSASCIIStringEncoding];

        if (COLOR_RED == i) {
            red = strtol(hexCode, &endptr, 16);
        } else if ( COLOR_GREEN == i ) {
            green = strtol(hexCode, &endptr, 16);
        } else if ( COLOR_BLUE == i ) {
            blue = strtol(hexCode, &endptr, 16);
        }
    }

    return [UIColor colorWithRed:red / 255 green:green / 255 blue:blue / 255 alpha:1.0f];
}