Number of colors present in specified palette.
Integer in range [8...256]. If palette field is non-null, this must less than or equal to the number of colors in palette field, and greater than or equal to maxColors field.
If no palette is specified ( palette field is null), this option is ignored and an optimized palette is automatically generated.
Return Value
Integer in range [8...256]. If
palette field is non-null, this must less than or equal to the number of colors in
palette field, and greater than or equal to
maxColors field.