Merge several color layers into one based on their transparency and alpha blending. In the final result, the lower layers are visible through the transparent or `NA` parts (if any) of the upper layers.
collayers.merge(collayers, opaque_background = "#FFFFFF")named list, the values must be vectors, matrices or arrays of color strings (as produced by rgb. The names are freeform and do not really matter. All values must have the same length.
a single color string or `NULL`. If a color string, this color will be used as a final opaque background layer to ensure that the returned colors are all opaque. Pass `NULL` to skip this, which may result in a return value that contains non-opaque color values.
a color layer, i.e., vector of color strings in a hemilist
Other surface color layer:
collayer.bg.atlas(),
collayer.bg.meancurv(),
collayer.bg.sulc(),
collayer.bg(),
collayer.from.annotdata(),
collayer.from.annot(),
collayer.from.mask.data(),
collayer.from.morphlike.data()