The set I wanted the most in my childhood life was the one my parents did not buy me: a set of Colorforms. Most of us at least in the USA remember these plastic film stickers which you could move around on a black background to make instant mid-century modern designs. Colorforms, as the site shows, expanded into countless ways of having fun with stickers but I still remember the original one, with its limited but pure repertoire of color and shape. With Photoshop you can re-design a digital version of the original and make it as simple or complex as you want. Maybe my folks didn't want to spend the money on the original Colorforms as it was kind of pricey for its time. But now I can use an expensive computer to do the same thing!
This design is done according to the concept of 3 colors plus black, 3 color-coded shapes, and 5 virtual sizes of each one. There were no lines available for Colorforms as I remember. This piece will be complexified with more graphic elements and added to the "K" series of Photoshop geometric abstractions.
Photoshop, about 5 1/2" x 5 1/2", March 7, 2018.