Among some of the numerical abnormalities a karyotype can detect are: Down syndrome (trisomy 21), in which an extra chromosome 21 causes distinctive facial features and intellectual disabilities. Edward syndrome (trisomy 18), in which the extra chromosome 18 translates to a high risk of death before the first birthday.
without the graph presenting the data you can't really answer this but I assume since o Neil pass has a green environment the mice would be brown to match the ground