These pieces seem to be a very different kind of abstraction, maybe connected more to abstract expressionism. (hamptonsarthub.com)
Frankenthaler had become a creator of a new kind of abstraction which became known as Color Field painting, using stains and color to seep into the canvas. (huffingtonpost.com)
The remapping ability then became co-opted for other kinds of abstraction that humans excel in, like the bouba / kiki metaphor. (discovermagazine.com)