
Each dog is different & a lot depends on the breeding behind your dog, some lines have lovely early maturing coats & poor(well poor IMHO)colour especially in the blenheims, others have lovely colour & slow to mature coats
I personally wouldn't want my dog to be in full coat & mature(they seem to go hand in hand)before they are 2 years old
To keep your dog looking good once he is in full coat requires a really good diet(doesn't need lots of additives ;) )regular grooming & good quality shampoo & condition. I use Quistel on my older boy, as I have mentioned many times he had a skin problem which it has cured, every time & the other two every third/four shampoo & I use Doreen Paige shampoos for the others. I have a herbalist/homoeopath friend who makes me a special leave in conditioner(he's done this for over 30 years), but there are commerical ones available. I must have a chat to Doreen about her developing one as her stuff leaves their coats with a gloss like a mirror & so soft & silky & smelling gorgeous
BTW I do not use a hairdryer as this makes the coat too dry & I use a blaster & drycoats after their baths