The mark consists of the following: a double continuous loop with colors, starting from the cross over or intersection of the small loop with the big loop, proceeding first along the big loop and downwardly along it, the color first being yellow; then gradually changing to orange and then at the bottom of the large loop, changing gradually into red; then proceeding up the large loop gradually changing into the color purple so that the color purple is on top of the large loop for a portion and gradually changing for the other portion of the top of the large loop into the color blue which extends to the intersection of the two loops, then, proceeding on the small inner loop, first in blue until the bottom of the small loop and then gradually changing into the color blue-green then proceeding upwardly on the small loop, into the color green and then at the intersection where the small loop changes over into the large loop back into the first mentioned color yellow. The color white is in the longitudinal middle of the large loop extending from its bottom to near its top and is meant to show that the loops have three dimensionality, i.e., the white serves as shading such that the loops, in cross section would be a circular shape.