The official colors of Sigma Phi Epsilon Fraternity are red and purple. Gold is utilized essentially as trim, but is not an official color. While gold is used on SigEp chapter flags for Greek letter chapter designations and as striping, it is NOT an official color of the Fraternity. While gold is used in the banners that have flown overhead at Conclave it is in the same regard, as a trim, but not as an official color of the Fraternity.
The official flowers of the Fraternity are red roses and deep purple violets. The Fraternity has two official flowers that match the same colors as the Fratenity's two official colors. There is not a gold colored flower that officially represents the Fraternity.
The same could be said of the flag of the United States of America whose colors are red, white, and blue. While gold fringe may be used in interior flags, gold is not an official color of the flag, but merely as trim --- identical in concept to the Fraternity's official colors --- and does not include gold as an official color.
Finally, and without revealing any secrets whatsoever of the Ritual, it clearly states the two very specific official colors of the Fraternity, red and purple, and for a very specific reason. Gold is NOT included.