[Nihil Obstat]

"...It takes its name from the red vestments, symbolizing the Holy Spirit, worn by the celebrants."

I think the red vestments symbolize martyrdom, to be prepared to be martyrs for the Truth like Saint Thomas More.

[Romulus]

So it does sometimes, but in this context the red vestments symbolise the Holty Spirit, which came to the apostles in the form of fire.