Yes, Taemin is likely the offspring of a black, blue, or otherwise mostly dark Japanese and a Mille Fleur d'Uccle (which are bearded). I say this because I've owned blue silkie/MF d'uccle crosses (i.e. I have a decent idea of possible variations on how d'Uccle can manifest) plus I've had Japanese. Ahh... the faces on those little guys. I suppose Serama is another possibility for the mother but from a statistical standpoint less likely lol.
The second one, I'd need a better look at his face. His body shape seems a little bulkier/rounder than I would expect with a Polish parent if the other is a d'Uccle.
I'm afraid I can't help much with color. Birchen should have silver/white hackle and saddle feathers. Yours look like they've got some color (maybe they are silver and the lighting is throwing me off) and I have never found a name for that pattern in gold.
A potential shortcut to use in describing them to someone else is "same pattern as birchen but light gold instead of white."
Thank you. No, the lighting isn't throwing the color off, they are black and gold. On Key and Minho (Minho isn't in any pictures, he looks almost identical to Key) their hackles are almost blonde or a straw color. Taemin's hackles and saddles are more gold. That's why I was confused. And I can get a better picture of Key's face in a second. When I got them, the lady told me(it was her daughter who was breeding the birds, she was just selling them) that they were polish crosses and Japanese crosses. She didn't specify which. Or what the other parent was. And I'm just very curious as to what my little babies are made of.