Liturgical Colour : Purple/Violet
Matthew 17 : 10-13

At that time, the disciples of Jesus asked Him, “Why do the teachers of the Law say that Elijah must come first?” And Jesus answered, “So it is : first comes Elijah to set everything as it has to be. But I tell you, Elijah has already come, but they did not recognise him, and treated him as they pleased. And they will also make the Son of Man suffer.”

Then the disciples understood that Jesus was referring to John the Baptist.