Orange is the colour for Thursday which is the day of the week on which Her Royal Highness Princess Chulapornwalailak was born.
Purple is the official colour of the Province of Nakhonsithammarat where the university is. The provincial colour is derived from the personal colour of Phra Rattanatachamuni, abbot of Thapoh Temple and famous education reformer and innovator of the southern region of Thailand in the reign of King Rama V, who is locally regarded as the pioneer of modern education in the south.