The main reason why Jason wears blue in concert is his love and respect for Jason, as well as the atmosphere and theme of the concert itself. Specifically:

1. Jason fans' support color is blue, so wearing blue clothes can express their support and love for Jason.

2. At the concert, blue light and glow sticks are also commonly used as entertainment tools, so wearing blue clothes can better blend into the atmosphere of the concert and cheer for Jason with other audiences.

Jason's favorite color is blue, so wearing blue clothes can also show his respect and respect.

In short, wearing blue clothes to watch Jason's concert is a way to express love and respect, and it is also a way to integrate into the atmosphere and theme of the concert.