What does three-point blue robe mean?

I broke into the house naked. In one of Zhuge Liang's prophetic poems, a blue robe broke into the house, saying that although Zhuge Liang wore a blue robe (symbolizing that Zhuge Liang had certain power), he broke into the house, which means that Zhuge Liang also came from a very poor rural area, that is to say, he broke into the house without wearing clothes.