十六进制的RGB转换过成color

if(hex.length == 3){

        hex = [hex stringByAppendingString:hex];

    }

    NSString *red = [hex substringToIndex:2];

    NSString *green = [hex substringWithRange:NSMakeRange(2, 2)];

    NSString *blue = [hex substringFromIndex:4];

    unsigned int redI = 255;

    unsigned int greenI = 255;

    unsigned int blueI = 255;

    

    NSScanner *scan_red = [NSScanner scannerWithString:red];

    [scan_red scanHexInt:&redI];

    

    NSScanner *scan_green = [NSScanner scannerWithString:green];

    [scan_green scanHexInt:&greenI];

    

    NSScanner *scan_blue = [NSScanner scannerWithString:blue];

    [scan_blue scanHexInt:&blueI];

    

    UIColor *color = [UIColor colorWithRed:redI/255.0 green:greenI/255.0 blue:blueI/255.0 alpha:1.0];