The final feast of the Easter season is Pentecost. Â Pentecost celebrates the day the disciples received the Holy Spirit, and the Early Church (Acts 2). Small flames appeared on their heads and allowed them to speak in tongues and proclaim the truth of Christâs resurrection, eternal life, and forgiveness of sins. Those who believed were baptized and received the Holy Spirit as well. This is the longest part of the entire Church year. Â Â
 In Lutheranism 101: Worship, Rev. Dr. Thomas Winger explains the scriptural foundation and historical significance of this day in the Church Year:
We celebrate Pentecost as the completion of the Easter season and the fulfillment of Jesusâ promise that He will send the Holy Spirit to His Church (John 14:15â31; 16:5â7). Pentecost is a celebration of the Spiritâs work, particularly in creating faith in the heart through Holy Baptism and preaching (Acts 2:38). But the Spiritâs work is to point not to Himself, but to Jesus (John 15:26). So Pentecost is still a festival of Christ.
The Christian Church has celebrated Pentecost since at least the third century, perhaps already in apostolic times (Acts 20:16). The color of Pentecost is red, recalling the tongues of fire on the disciples (2:3). (p. 124)
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"Color. Color is everywhere. Color is God's way of filling his world with beauty and giving pleasure to those who live in this colorful world. Christians, for centuries, have used color in divine worship to emphasize the redemptive action of God through his Son."
"Red is a power color and is appropriate for use on Pentecost Sunday. On this day we remember the power and fire of âthe Lord and Giver of Life,â who revealed himself as the promised one. The color red communicates the motif of strength-strength and power the Holy Spirit gives in order for God's people to call on the name of Jesus Christ and share that powerful name with others."
"The Sundays following Pentecost, observed as âthe time of the church,â share a somewhat similar theme as that of Epiphany. Affectionately called the season of the âgreen meadow,â no doubt due to the fact of green being the established color, these Sundays also emphasize the subject of growth.
Green is a neutral color, but there is nothing colorless about our need to grow and mature as disciples of Jesus Christ. That's why the âgreen meadowâ time of the church year is so lengthy."
*Quotations taken from "The Colors of the Liturgical Seasons" by Rev. Douglas K. Escue
To learn more about the colors of the church year, read Rev. Escue's full article here.