There are different ways to get the color buff. And different ways to get gold necks. Some gold necks have, is it? Dominent white, that dilutes both red and black, while other GN have blue, which dilutes only the black. Also, some millie fleurs have the darker mahoghany color, while others have the diluted buffs. Since we still don't know the genetics for all the different buffs, it's easy to get a bird with one dilute, no dilute or two dilutes. Just find one of your birds that are walking around with the darker color and breed to it. Keep away from the lighter ones, if that is your concern. I love both the light and dark millies.Your golden neck roo is a lot darker than mine. I'm wondering how I can darken up what I produce from mine