Gene responsible for body color

Imagine discovered a gene  responsible for body color. The wild-type form allows for a tan body color and the mutant form causes a dark-brown body color. Following the standard Drosophila nomenclature, what would be the name of this gene: “tan” or “dark-brown”? Why/how do you know?The MC1R gene provides instructions for making a protein called the melanocortin 1 receptor. This receptor plays an important role in normal pigmentation. The receptor is primarily located on the surface of melanocytes, which are specialized cells that produce a pigment called melanin.