8. There are 60 colored balls in a cloth bag, with 6 balls of each color. If you draw balls with your eyes closed, to ensure that there are three balls of the same color among the drawn balls, you need to draw at least $\qquad$ balls.
Analysis: $60 \div 6=10$, there are 10 types of colored balls. Considering the worst-case scenario, if 2 balls of each color are taken, taking one more ball will ensure that there are three balls of the same color among the balls taken. Therefore, the answer is $2 \times 10+1=21$.