Just in case you are wondering...

...what a Delicolor is, it is a vintage stage lighting control.



It was designed by Rollo Gillespie Williams who moved from Holophane to Furse in the 1940s.

The Delicolor bits are to the left and bottom (and right on the uncropped picture if you click through). You turned the dial to the desired colour, wound the handles... and Voila!