12. There are 8 black, 8 white, and 8 yellow chopsticks mixed together. In the dark, you want to take out two pairs of chopsticks of different colors. How many chopsticks do you need to take out to ensure you meet the requirement?
12. 【Solution】10 chopsticks, possibly 8 black, 1 white, 1 yellow, among which there are no two pairs of different colors.

If 11 are taken, since $11>3$, there must be two of the same color forming a pair, let's assume this pair is black. Removing these two, 9 remain, among which the black ones are at most $6(=8-2)$, so the white and yellow chopsticks are at least $3(=9-6)$, and among these 3, there must be 2 of the same color forming a pair. This way, we get two pairs of different colors. Therefore, at least 11 need to be taken.