EASTER is a joyous season in which we celebrate Christ’s resurrection and ascension, as well as the coming of the Holy Spirit and the beginning of the Church. This is a time of rejoicing when ALLELUIA should be sung with heartfelt emotion.
This season flows from the Easter Vigil and concludes fifty days later on Pentecost Sunday. The last day of the EASTER season is Pentecost Sunday, on which we celebrate the coming of the Holy Spirit. On this day red is the liturgical color, representing the Fire of the Holy Spirit.
A symbol for EASTER is the Paschal Candle and water which represent the light and new life of Christ’s resurrection and the water of our baptism and rebirth. The color used during the EASTER season is white signifying the joy of Christ’s resurrection. (On Good Friday, black may also be used as a symbol of death.)
Source: http://stjamesfarmington.ctdiocese.org/Christian_Education/Church_School/Church_School_Schedule/Resources_for_Parents/Colors_of_the_Liturgical_Seasons