Ella Fitzgerald covers Billboard magazine:
"The Coming Battle: RADIO vs. MOVIES"
Design director Josh Klenert
explains to me: "after Billboard started covering the entertainment industry, during the mid-1940's through the mid-1960's they ran B&W photos with large areas of spot color. Each week they rotated between red, yellow, blue and green ink. Its my hunch that this is what led to the logo redesign in the summer of 1966 (with the red, yellow, blue and green dots) which has stood since then."