I have recessive white Orpington bantams which come from my Blues/Blacks. The White Orps are to have the white/pink feet also, but my White Orps have bluish legs (more than likely due to E or ER genes, as the day-old white chicks have patchy blue/white feet).

Above: Recessive White, Blue & Black Orpingtons, all E (extended black) or ER (birchen) & White skinned (W/W).

The above recessive white bird may also be blue (Bl/bl) or Splash (Bl/Bl), but haven't tested him. I have a younger white cockerel that has lighter blue legs. Kind of hoping I'll get Recessive White/Splash birds with only slight hint of blue. Otherwise it's a hard slog to get the correct leg colour.

Musaland, your quest for white-legged White Marans is much easier, considering your whites are from Cuckoo. It should be easy to obtain if the white roos are homozygous for sex-linked barring (B/B), although the hens may have a hint of colour, as can only have one dose of the Barring gene (ie hemizygous). Is the Cuckoo father of the white chicken, homozygous for sex-linked barring (B/B), ie Light Cuckoo? If he is heterozygous (B/b), the white pullet may possibly be non-barred (b/-) & show more melanin on the legs.