Shimmer
Examples
Basics
Shimmer causes the fur and feathers to take on a faint iridescence, similar to crows and grackles. In your ketucari's genotype, shimmer is denoted by the letters "nSm" (heterozygous) or "SmSm" (homozygous). In its heterozygous form, shimmer has a pass rate of 25%. Homozygous shimmer has a 50% pass rate.Color and Shape
Shimmer should be soft-edged and not overpower the colors beneath it. It may be one color or consist of several color shifts. In order to avoid confusion with glass, shimmer may not be white. Shimmer does not actually change the colors of the feathers like other markings, but rather creates a sheen over the feathers that changes with the lighting:
Source
Here are some tips on how to get this look:
Range
Since shimmer can appear anywhere on the body, there is no minimum range diagram for it. It must cover enough of the body that it is immediately recognizable.
Interaction with Other Markings
Shimmer goes over all markings, even white marks. Shimmer is not affected by axanthism, inversion, erythrism, or leucism. Shimmer should be transparent enough that markings beneath it are still visible, like the sable below:
Shimmer should be fairly subtle. The shimmer pictured below is much too bright and loud and looks more like a solid marking than a sheen on the coat. Be sure that the base coat is still recognizable beneath the marking.