In fact, the partridge color is pretty much standardized in Europe and I know a lot of breeders who have excellent specimens with excellent, clear silkies in partridge color. The problem is with the blue and lavender color, which are very rare. Likewise, in Europe there is a problem with red silkies , which is not like in the rest of the world (at least as far as I can see on the internet), the red EU silkies are quite bad.
Here is the standard for partridge color, so you have some guidelines:
The partridge
Male plumage: Head and crest dark orange. Hackles orange/yellow, free from washiness,
each feather having a clear black stripe down the centre. Back and shoulders dark
orange. Wing bar, solid black; primaries black, free from any white; secondaries, outer
web dark orange, inner web black, the dark orange alone showing when the wing is
closed. Tail and sickles black. Leg and foot feather black. Breast and fl uff black. Undercolour
slate-grey, free from white.
Female plumage: Neck and breast lemon striped black. Hackle feathers black centre
with lemon edge. Crest, lemon and black mingling. Body, including wings and cushion,
black barring on soft partridge-brown. Undercolour slate-grey. Leg foot feather colour
as the body. Black permissible in the tail.
