For the color question lets use Person A B C. A said he don't know his color, which means there are no Blue Blue.And then B said he don't know. Which mean he see no blue on C. If he see C is blue, then B knows he is red. This is because of what A said make sure there is no blue blue between B and C and C is blue B knows he is red for sure. Since B said he don't know, which indicate that A can be either blue or red but C must be red.