This program was originally written for Windows platform. On Mac and other operating systems, depending on versions and/or browsers, the various colours on the colour box at the bottom of the graphing calculator may not show. Also you may have to double click on the coordinate plane if a button does not function as intended.
If you are using Mac or other operating system that use double buffering to display graphics, the animation option will not work. In these cases select none for Animation to save time.