As VolunteerChins mentioned a simple white mosaic is genetically the same regardless of the phenotype expression. However there are multiple genetic types of "white" chinchillas eg: pink whites, ebony whites, white violets, white sapphires, TOV whites, etc. Pink whites and tan whites will have brown markings, where as white mosaics and ebony whites will have light to dark gray and/or black markings. TOV whites tend to have more of a veiling of gray/black covering their face and/or back. White violets have violet markings and white sapphiers have sapphire markings.
The phenotype of each genetic type can range vastly from almost pure white to almost all gray, black, beige, tan, violet, sapphire with slight white markings. Genetically though a pure white pink white is the same as an all beige pink white with a white tipped tail.
Cheryl