Each day of Navratri is associated with a different color as mentioned in this article.
How are Navratri colours decided and why do they change every year?
The first colour of the Navratri is decided based on the week day when the festival begins or when Ghatsthapna or Pratipada falls. The remaining eight days then follow a fixed cycle of colors. Each day is dedicated to one particular form of Goddess Durga. Here’s a look at nine different colours to be worn on each day of Navratri 2017 festival according to Drik Panchang.
Is there any scriptural basis to this selection?