Mini has the most beautiful dilute colors. She is what is known as a dilute tortie (at least that is what the rescue said when she was a kitten).
A Dilute Tortie cat is a cat with traditional tortoiseshell coat coloring that is more pastel and less vibrant. The coat pattern appears diluted with blue and yellow colors and less orange and black. Dilute Tortoiseshell cats are not a breed of their own and are a variation of a tortoiseshell cat.
Dilute torties have a specific genetic makeup that creates their unique diluted, double-color pattern. It is important to note that similar to calicos, Tortie cats, including the diluted ones, are almost always females.
This plays into creating their coat because the X chromosome carries the “instructions” for how their fur is going to look. So if a cat is a female and has two X chromosomes, it means they have received two instructions for their coat pattern, and this is where we see multiple colors being blended. – https://faqcats.com/what-is-a-dilute-tortie-cat/