The Geogebra website has added some nice features since the last time I used it. It is easy to make models of 3-dimensional shapes. The video below shows the steps I followed to make a cone and shade the base and lateral area with different colors.
There are lots of false starts (losing the axis and not being able to stop the spinning was not clever) as I do this, but within about 4 minutes I had a shape ready to be screen captured. Here are some other images I made earlier today.