Colored output

caution

This section is about a feature of C++ that is only present on the Windows platform. If you are using another operating system, feel free to skip this part without any problem.

A nice little feature that we have in Windows with C++ is the ability to change the text and the foreground color in the console window.

There are mainly two ways of doing that.

system("color XX")

The iostream header file allows us to use the command system("color XX"); to change the entire colors of the console window. After the world color there are two characters: the first controls the color of the background while the second controls the color of the text.

#include <iostream>
using namespace std;

int main() {
    system("color 0A");

    cout << "green!" << endl;

    return 0;
}

Try to run this program and experiment by changing 0A with other numbers or letters. These are the different colors you can use, each with its corresponding ID.

Color ID	Color	Color ID	Color
1	Blue	9	Light Blue
2	Green	0	Black
3	Aqua	A	Light Green
4	Red	B	Light Aqua
5	Purple	C	Light Red
6	Yellow	D	Light Purple
7	White	E	Light Yellow
8	Gray	F	Bright White

SetConsoleTextAttribute

An alternative of using system(); is the SetConsoleTextAttribute function in this way:

SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), color);

where color is a numerical value to which it corresponds a certain color.

The difference with this method is that you can modify individual output colors. See this example by vegaseat:

// colorAttribute = foreground + background * 16
// to get red text on yellow use 4 + 14*16 = 228
// light red on yellow would be 12 + 14*16 = 236

#include <iostream>
#include <windows.h>
using namespace std;

int main() {
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);

    // you can loop k higher to see more color choices
    for(int k = 1; k < 255; k++) {
        // pick the colorattribute k you want
        SetConsoleTextAttribute(hConsole, k);
        cout << k << " some text" << endl;
    }

    cin.get(); // wait

    return 0;
}

note

There's a for loop in the code above. Don't worry if you don't know what it is or what it does. We'll discuss what loops are and how they work in a future chapter.