Matthew 27:27-31

The stripped him and put a scarlet robe on him.

In Matthew it is a "scarlet robe" (a soldier's outer garment).
In Luke it is a "elegant clothing" (Luke 23:11).
In John he is dressed with a "purple robe" (outer garments) (John 19:2).
In Mark it is simple a "purple" (garment) (Mark 15:17, 20).

For Mark and John, the purple speaks to the wealth of Christ and his royalty, even in the midst of his humiliation. In Luke, the one who identifies with the poor and lowly (even in his birth) is mockingly clothing with the clothes of the rich. But in Matthew, the robe is scarlet, the color of blood, because by his blood, Christ will make atonement for the people.

In the film The Passion of the Christ the scourging scene is the most difficult to stomach, perhaps rightly so.