If I'm talking too much - just tell me... Its too dang hot out there to do anything else!
You would get Silkie chicks.. I hope...
The reason you don't see that answer is it is not an easy answer. You don't usually use a White in any other pen except a White pen. You need one copy from both parents to get White - because most Silkies are recessive white. If you outcross to a Blue - you will get Blue/Black plus whatever genes are hiding under that White once you take one copy of Recessive White off. Who knows what that is.... You can get almost anything, except possibly Buff or Mottled/Calico, and it will carry one copy of recessive white for future breedings.
I have a Black/Red Partridge Rooster that I just found out carries recessive white. So now half of my blue/partridge/black/etc chicks could produce white... and I do have a White from him (which carries Partridge and maybe blue). Because one of my Blue hens also carries Recessive White..
They don't need it 6' tall - but you might. Otherwise that is plenty of room for 4 birds - they are bantams.. you might get up to 10 comfortably. You won't be able to breed Blue and Splash with White - those are not compatible - see above.
What breed are the older chicks? If they are Silkies it might work, maybe. If they are other breeds it depends on their temperament. I have some 8 and 6 week old chicks together, they get along fine. I also have some 4 week old chicks with some newborns, and I think I am going to have to move some of those over to the 8 & 6 week old pens.. those poor littles get bowled over and stepped on a lot. Good thing they are cross breeds and very hearty. I would not do that with newborn Silkies - I have a separate place for them.
