Color of the Soul

Every bushi has a different colour soul, and when a bushi touches a kitetsuto the materials in the sword shine and reveal the colour of the soul. In Kojiros case he shone blue, witch was reveald to be a common colour, since 2 out of 5 bushi have blue souls. In total there are 5 different colours red, white, green, yellow and blue. Of the five red and white are the most rear. Most bushi are one of these colours but there is one none exception, that being Musashi. And it turns out that if ones soul is black they will never be acknowledged by a kitetsuto.