The OpenGL function glColor3f is one form of the set of functions for establishing the current drawing color. The suffix part 3f states that the color is given with three float values corresponding to the red, green and blue components of the color. For example, the call glColor3f(1.0, 1.0, 0.0) establishes the current drawing color as yellow (full red, full green and no blue). In turn, the current drawing color remains in effect while constructing geometries until another call to glColor is made. We study color along with other forms of the function glColor with the tutorial Color Models.