Also, I think they said a lot of the alien heads consist of an alien with one big 'eye' and one little 'eye', lol.

Donuts are roundish yellow spots with a dark spot in the middle, inside a darker area. Keyholes are similar, but are attached to the back stripe. (If I remember correctly).

I actually started to be able to see it, but then I have some granite-like babies who seem to have the markers too. >_>