C++で列挙型を使う

c1 ->1

#include <iostream>   

enum color {
    Red,    
    Blue,   
    Green,  
};

int main(int argc, char const* argv[])
{   
    enum color c1;

    c1 = Blue;
    
    std::cout << "c1 ->" <<  c1 << std::endl;

    return 0;
}