This Cartoon Model has been colored according to the index of each amino acid in the polypeptide chain. Since Proteins are linear molecules, this yields a nice color interpolation from red at the beginning of the molecule to blue at its end in the default coloring settings.

When you press Next, an energy minimization will start. You can watch the molecule's structural changes. We will perform 20 steps and the current step number will be shown in the statusbar at the bottom of the main window.

Don't worry if the simulation takes a moment to start.