What you should know first

This is all about a class called wash_separately and the ANSI-code insertion it performs on the stream it encapsulates.

Go to the reference manual.

Example:

#include <iostream>
#include "wash_separately.h"

int main() {
    wash_separately ws(std::cout);
    ws << "Hello, " << foreground(0,0,255) << "world" << reset() << "!\n";
    return 0;
}

Output:

Hello, world!