Code:
glEnable(GL_BLEND);
glBegin(GL_QUADS);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glColor4f(1.0f, 1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glColor4f(0.0f, 0.0f, 1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd();
glDisable(GL_BLEND);
and the results: