There are some good comments in the post below about Sarum liturgical colors.
The whole business about colors in the liturgy is somewhat obvious. My suspicion is that the Church merely had a gut level response to what was appropriate. Red, gold, white are "happy" or "energetic" colors. Black, blue, violet, are "sad" or "placid" colors.
As Papa Ratzinger said in The Spirit of the Liturgy, the liturgy is cosmic, and colors, being part of this cosmos, are sacramental and thus reflect feelings and realities beyond themselves.
All that being said, these Orthodox hierarchs pictured above look legit. Can I get a witness?