Bauhaus tops
Bauhaus artist Ludwig Hirschfeld-Mack designed these Optischer Farbmischer (optical color mixer) tops in the early 1920s. Reproductions by Naef are available from Fawn & Forest for $49. From the product description:
Bauhaus tops (Fawn & Forest, thanks Kelly Sparks!)The first production of this toy started in 1977. The "Bauhaus Optischer Farbmischer" shows us how the rotation of a top brings about a color blend. Varying aspects of color theory are deomonstrated on the reverse of the inter-changeable color discs Not for children under 3 years old.

The first production of this toy started in 1977. The "Bauhaus Optischer Farbmischer" shows us how the rotation of a top brings about a color blend. Varying aspects of color theory are deomonstrated on the reverse of the inter-changeable color discs Not for children under 3 years old.
the latest
latest episodes
Didn't Robert Musil invent the wheels and Hirschfeld-Mack invent the toys?
Not sure! I Googled but couldn't find much about the original designs (in English, anyway).
MinnesotaJ: You're right, according to Musil's bio on http://www.musilmuseum.at/robert-musil-bio.htm and Wikipedia. There's even an article about his invention, albeit in German: http://de.wikipedia.org/wiki/Musilscher_Farbkreisel
In short, his color wheel was continuously rotated by a drive shaft and you could change the size of the colored segments whilst operating the device. He used it to test color perception and physical effects.
Great info. Thanks, FORLAIN!
Robert Maxwell had a wheel with variable sectors. Here's a reference to how to make one. I think the Royal Society still has one of his original wheels, but I couldn't find a picture. Still, here's a reference on how it worked...
http://personales.upv.es/gbenet/teoria%20del%20color/water_color/colortop.html
I think Ignaz Schiffermüller came up with a circular plot of hues, and not anything that actually spun, which is a pity as someone with a name like that ought to have something named after hum. However, colour circles and even colour solids are a lot older than that.
Wait a minute... they mean 49 cents, right? I mean, inkjet printers still exist right?