But it occurred to me that in this context, "cock's plumage" would work as a joke to describe the fancy hat worn by the разведенная кошка (i.e., making a joke that she had symbolically cut off her husband's wang...)

In other cases, however, "rooster's plumage" avoids any possibility of an unwanted double entendre.

P.S. Perhaps an approximate Russian equivalent might be saying "лазурные мечтания" instead of the more traditional phrase "голубые мечтания"?