I took Professor Thomas's fiat lux class See the Colors: Glimpses of What We See and How We See Them winter quarter of 2009. If you are a psychology major you really need to take his class. It is essentially a slightly easier version of half of the material you will need to know for the first midterm for Psychology 120B. I was shocked at how useful this background was. I'm taking 120B with Kellman right now, the class average on the midterm was 37 out of 50. I pulled a 49 and I attribute that almost entirely to having taken Professor Thomas's fiat lux. As for the fiat lux itself, it's essentially a quarter on color vision, you have one reading assigned per week that usually is pretty short and then you discuss it in class. You also need to volunteer once to give a 30 second summary of one of the readings. The readings were pretty interesting, you learn about Newton playing with prisms and jars and about monkeys that get all excited to do a color matching game (I think they fed the monkeys when they matched colors correctly). Its a pretty good class all in all and if you are a psych, psycho-bio, or cognitive science major, you really ought to take this class because it will help a lot when you have to take Psychology 120B.
Professor Thomas is nice, funny and really cares about his students. The material he teaches is quite difficult and the textbook is very hard to read, but his lectures are quite effective although I wish he'd post the slides online. His grading scale is more than generous and he's a truly nice professor. I definitely recommend taking a class with him if you can handle tough material.