you need to colour feed gnasher soon as the bird starts moulting I use carophyl best around,i usually start old birds in the water on there second round as they start moulting the odd feather and then in there water and egg food for chicks on the third round,first round of chicks get colour feed 1 week after been took out of nest, I don't feed seed to young canaries to completely coloured, I use egg food ,crushed bread crumbs ,soak seed .a little touch of aniseed oil all with colour feed until all chicks coloured up then introduce seed to them hope this helps