I'm really curious how old you are. The great grand-dad part makes you think you're my age or a bit younger, but then I grew up very middle class and I don't know if I've ever even seen a black-and-white TV.
From googling just now, color sales exceeded black and white by the 70s. However, new black and white models were still being introduced even into the 90s in the U.S., particularly in the budget or portable segments, and were still being sold new into the 2000s.