The colors that are seen alot on Shinkouhyou. I based these ideas on chinese mythology. May not be accurate.

black=yin Represents all feminity, the earth, darkness. Sometimes associated with evil. It is usually represented by the moon and dragon in chinese mythology.

white=yangRrepresents masculine forces, the heaven, light, and dramatic changes. Represented by the sun and tiger.

black and white together, especially on the yin-yang symbol stands for the changes that never stop changing, like the forces on the yin-yang symbol. ^^;;