A light weight electrochromic dimmable mirror stack (300, 600) is presented that is composed only of solid-state layers (315, 615) with a total thickness of less than 50 micron and a reflector (310, 610). Normally such a kind of layered device suffers from iridescence due to interference of light waves reflecting at the interfaces between the layers of the electrochromic device. The solution provided by the invention is to pattern at least one of the layers (315, 615) in the device such that the interference effects are smeared out and a more neutral color is obtained. Various possible configurations are described and also the method to produce such a device.