"Silver" could be a few different mutations.... it could describe Blue - Blue and Golds, Blue Opaline Blue and Golds or Blue Scarlet Macaws. Talk about confusing!!!
I kind of love the Blue Opaline B&G's personally! Which seems kind of silly, because a Blue Opaline B&G is close to the coloration of a Blue Scarlet... but I'm not interested in the Blue Scarlets!
Blue Scarlet
[ame="https://www.youtube.com/watch?v=pofsAbSn4b8"]White Macaw - YouTube[/ame]
Opaline B&G
[ame="https://www.youtube.com/watch?v=2YDDj2a9yqU"]Genetic mutation, Rare bird, Blue-and-yellow Macaw, - YouTube[/ame]
Blue B&G
[ame="https://www.youtube.com/watch?v=BPxgnhp7JG8"]Silver Mutation Macaw In Wild - YouTube[/ame]
Blue Opaline B&G
[ame="https://www.youtube.com/watch?v=BAcKG5zG0H8"]Meet Silver macaw parrot the 7 month opalineblue mutation or silver blue and gold macaw parrot - YouTube[/ame]