One Service on the church lawn.
...before Jesus ascends to heaven, he promises that he will not leave us "comfortless", but will send the Holy Spirit to strengthen and guide us, to guide the church...
Acts 2:1-4 And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
So... on The Day of Pentecost in the church year, fifty days of Easter and ten days after the Ascension, the clergy wear RED vestments to signify the work of the Spirit. It is also a custom in many churches for the people in the congregation to wear RED on the Day of Pentecost as well. We wear RED to remind us of the fire of the Spirit.