What does it mean to take off the yellow robe and put on the red robe in Tongsheng?

I am the noblest of all flesh and blood. I will enter school early, when I will be thirty-six years old. I will take off my blue shirt and put on a red robe.

Most of them are proverbs that criticize life, meaning that after 36 years old, you are dead. Take off your blue shirt and put on a red one. Blue shirt and red robe are the symbols of ancient official positions, that is, the performance of adding officials to the ranks.

I hope it helps you. If you are satisfied, please adopt it!