Individuals in the
mollusk species
Donax variabilis show diverse coloration and patterning in their phenotypes.
The phenotype of an organism is the whole set of characters (or traits) of that organism.
It does not mean just 'what you can see on the surface'. Rather, it means anything which can be made visible by suitable means. For example, blood groups are definitely a part of the phenotype. However, they are not visible just by looking at a person.