Colorforms were invented in
1951 as an adult's toy. They consisted of five pages of
vinyl geometrical shapes:
circles,
squares,
triangles...plus a few other bits, all in
primary colors. There were four
plastic-covered blank pages (also in primary colors) to stick them on. Still available in some art stores and
museum shops for substantially more than the kids' version.
Funny, how adults now play with kids' toys and don't have that many of their own anymore.