Yup, thats normal :]
The tryptamine yawns are very common...I get them with aya, mushrooms, dmt, lsd, but i'm not sure about mescaline..With mushrooms especially i've gotten them dozens of times in a night before. its very pleasant!
'rainbow yawns' is actually in the nexus's lexicon..there i described it as a hyper ether brain massage to the sound of an earthquake
<Ringworm>hehehe, it's all fun and games till someone loses an "I"