Whats happened is since the parents don't share the same mutations the chicks have come out visually as the dominant "wild type" grey. to produce visual pieds both parents must carry the gene either visually like the father or split (where they have a white patch behind the head) since the mother is not pied or split pied you won't get any visual pieds
To produce a pearl the father MUST be a visual or split pearl as female pearls will only pass it down to sons as splits (hidden) since you don't have any pearls we can assume your male does not carry this mutation
But you look to have whiteface chicks, this means the father is split whiteface.
the chicks will be useful in future pairings though, as they will all be split pied and the males also split pearl