Yes these images must have been standard for a long time. Just checked a colorful encyclopedia (Salvat Estudiante) that I have had here at home since I'm a kid, the publishing year is 1976 (so I was seven by then), though I probably "finished" it when I was 10. This was one of those encyclopedias you had to buy issue by issue in kiosks, and then bind the volumes after finishing each one, loved to collect those when I was a kid. In this encyclopedia I just looked for "Daltonismo" (Color Blindness in Spanish) and sure enough, they have an example of an image just like these, but with a number 3 in it.
Actually rather interesting this example in the book. Reading the text, it turns out color blind people will see a number in it, but instead of a 3 they would must likely see an 8!!! Double checking the image, I now notice that indeed the left side of the ends of the 3 continue with some specific green color different from the general mix of surrounding greens in the background, actually closing the loops, so in fact forming an eight, only with the left half in green, the right half in red, sort of. Hand't I read that I wouldn't have noticed the eight. Will take a pic and post it.