Would you think that this unlucky in the dog world?

i made a new friend over the last few days and she has a BC dalmatian puppy hes 8 months old and hes a real cutie. but i have notice that one of his eyes is blue and the other eye is brown. my mum said that this is unlucky for the dog. if this is true how is it unlucky. My dad was very superstitious and i think it rubbed off my mum. does anyone else think that this is unlucky for the dog to have this