Balls:

There are three balls. One is red. Each of the others is either white or black. Now I give you a choice between two lotteries.

Lottery A: You win a prize if we draw a red ball.
Lottery B: You win a prize if we draw a white ball.

Which lottery do you choose?

Now I give you another choice between two lotteries.

Lottery C: You win a prize if we draw a ball that's not red.
Lottery D: You win a prize if we draw a ball that's not white.

Which lottery do you choose?

Post your answers, plus any reasoning, in the comments. If you're already familiar with the Ellsberg paradox, you can just watch. Explanations to come later.

UPDATE: Glad this is getting so many comments. Just a few comments of my own:

(1) Many people are assuming that each of the two balls is white or black with a 50-50 probability. Maybe, maybe not. Just keep in mind that it's not part of the assumptions.

(2) Just in case you reject the problem because you don't know the probabilities of white vs. black (though you shouldn't), you can answer the question assuming there's a 50-50 probability. Then, just for fun, answer the problem again where white has a 49% chance.

(3) Also, some people are wondering about the motivations of the "house," i.e., whether it wants you to win or lose. Think what you like about the motivations of the house, but keep in mind that the colors of the balls (however determined) are the same in Part 1 and Part 2.

(4) Some of you are wondering what's the "paradox." I'll explain soon (or you can just look it up on Wikipedia). It may not be right to call it a paradox; perhaps it's just an illustration of an interesting aspect of how people make choices.