Now, you need to decide at this point whether you're making a 256-colour game or a hi-colour game. 256-colour games have a lower system requirement, since they run faster, and they allow you to do palette effects. However, managing the palette is quite complex so you may wish to start off with a 16-bit colour game.
Click on "Palette" in the left-hand tree window. You will see the palette display on the right. If you wish to use hi-colour, click the "Convert game to hi-colour" button now.