Here is a picture of the function z^2. Notice that the spectrum of colors occurs twice as you circle around the origin. Also notice that the shading is darker near 0 and lighter for large z than the standard coloring of the plane. If you look carefully, you can see that the color sectors are half as wide and the shading annuli have been changed in size, when compared with the standard coloring. The positive imaginary axis is colored cyan or light blue because the values of z^2 are negative there and the color of the negative reals in the standard plane is cyan.