According to Wikipedia, IMBD, and other sites, The Blob started out as gray, they became redder and redder as it consumed more people. The 1958 film was in color, but when it was broadcast in the early 60s, most TVs were still black & white.
Leave us not forget Pogo, Thimble Theatre (Popeye), Moon Mullins, The Little King (I believe he was an ancestor of Lio. Neither speak.), Flash Gordon, Buck Rodgers, Mark Trail, and on and on and on ad infinitum.
A Study in Orange With a Mango.