Iniciales Arco iris OpenGL

Hola aquí les traigo las iniciales de ingeniería informática y sistemas de colores al igual que un arco iris

=====codigo===========
#include <windows.h>
#ifdef __APPLE__
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

static void display(void)
{
    glClearColor(0,0,0,0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glShadeModel (GL_SMOOTH);

    //I1
    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(-0.8,-0.8);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(-0.8,0.8);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(-0.4,0.8);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(-0.4,-0.8);
    glEnd();

    //I2
    glBegin(GL_QUADS);
        glColor3f(1.0,0.2,0.0);
        glVertex2f(-0.2,-0.8);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(-0.2,0.8);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.2,0.8);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.2,-0.8);
    glEnd();

    //S
    //barra horizontal arriba
    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.4,0.8);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(0.8,0.8);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.8,0.6);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.4,0.6);
    glEnd();

    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.4,0.6);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(0.6,0.6);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.6,0.0);
        glColor3f(1.0,0.0,1.0);
        glVertex2f(0.4,0.0);
    glEnd();



    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.6,0.0);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(0.8,0.0);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.8,-0.6);
        glColor3f(1.0,0.0,1.0);
        glVertex2f(0.6,-0.6);
    glEnd();



    //barra horizontal debajo
    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.4,-0.8);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(0.4,-0.6);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.8,-0.6);
        glColor3f(1.0,0.0,1.0);
        glVertex2f(0.8,-0.8);
    glEnd();

    //barra del centro
    glBegin(GL_QUADS);
        glColor3f(1.0,0.0,0.0);
        glVertex2f(0.4,0.1);
        glColor3f(0.0,1.0,0.0);
        glVertex2f(0.4,-0.1);
        glColor3f(0.0,0.0,1.0);
        glVertex2f(0.8,-0.1);
        glColor3f(1.0,0.0,1.0);
        glVertex2f(0.8,0.1);
    glEnd();

    glutSwapBuffers();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(640,480);
    glutInitWindowPosition(10,10);
    glutCreateWindow("Cubo");

    //glutReshapeFunc(resize);
    glutDisplayFunc(display);

    glutMainLoop();

    return EXIT_SUCCESS;
}