Calico is a work in progress with few serious breeders and no agreed upon working standard. Since calico is a splash bird showing autosomal red, it's offspring will always inherit a blue gene. Exactly what gene or genes cause autosomal red has no complete agreement among those interesting in or researching poultry genetics. From experience, offspring are likely to inherit.
Mixing colours indiscriminately may give you colourful birds, but they will carry a mish mash of genes that will be difficult to replicate.
Mixing colours indiscriminately may give you colourful birds, but they will carry a mish mash of genes that will be difficult to replicate.