7 Horses of Sun

The Sun is visualized as riding a chariot driven by Aruna (the period before sun rise is known as Arunodayam) and drawn by seven horses-the seven kiranas - 7 different wave lengths –the famous VIBGYOR – the seven colors of Violet, Indigo, Blue, Green, Yellow, Orange and Red. http://www.swamysharanam.org/articles/Thoughts%20on%20Makara-Sankranthi.htm