How to separate pen and brush colors

What is the right way to get different color
effect for pen and brush drawing object in OpenGL ?
I mean how to draw the frame lines in one color and to fill in another color.
I know that its possible to do it drawing the same object twice - but maybe there is smth more effective?

OpenGL does not have any concept of brush or pen, so you have to draw it twice if you want different colors of border and the filled color.