i dont know. i guess its suppose to be shading or something, cause when i "orbit" my sketch the panels change colors.
but that wouldnt make sense why the ones you think would be shaded would be purple, but arent.
they look purple from every angle //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif