The Latin phrase on Northwestern's seal, Quaecumque sunt vera (Whatsoever things are true) is drawn from the Epistle of Paul to the Philippians 4:8, while the Greek phrase inscribed on the pages of an open book is taken from the Gospel of John 1:14: ο λόγος πλήρης χάριτος και αληθείας (The Word full of grace and truth). Purple became Northwestern's official color in 1892, replacing black and gold after a university committee concluded that too many other universities had used these colors. Today, Northwestern's official color is purple, although <answer>white</answer> is something of an official color as well, being mentioned in both the university's earliest song, Alma Mater (1907) ("Hail to purple, hail to <answer>white</answer>") and in many university guidelines.
What color besides purple is often considered an official color of Northwestern?
white