as for the bird above, it is mottled, and it does have blue for sure, but it's not a blue millie, it has no blue mottling to it at all. Looks similar to a blue tailed buff with light mottling to it. If millie, it would have the blue spots too. Beautiful though.
As for one page back on the GN to the lemon question. A lemon millie is a millie fluer color with the gold diluter "cream" added to it. If you bred a goldneck to it, you would get diluted goldnecks, as the dominate white gene in goldnecks would erase all the black colors on the lemon millie. Several back crosses would have to be done to the leomon, but you possibly could eventually get back to it, that dominate white can be a bugger to clean up though.
Would be best to breed lemon cream millies to normal millies. Should get F1 lemons that way with no dominate white issues.
With the goldneck, they would look similar to that mottled bird above that doesnt have any dark spots.
