The Duck ABC's :
If you want something that is temporary, but last 6 months, then check a bee supply company. They have a paint that can be applied to queens to identify them. This paint is safe for birds. You can apply it to the skin of the leg or onto their toe nails like polish.
https://www.dadant.com/catalog/product_info.php?cPath=30_55&products_id=601
This link shows the yellow one, but they have other colors available.
Cool tip! THANKS!
I've used food color but it seems to fade real fast.
If you want something that is temporary, but last 6 months, then check a bee supply company. They have a paint that can be applied to queens to identify them. This paint is safe for birds. You can apply it to the skin of the leg or onto their toe nails like polish.
https://www.dadant.com/catalog/product_info.php?cPath=30_55&products_id=601
This link shows the yellow one, but they have other colors available.
Cool tip! THANKS!

I've used food color but it seems to fade real fast.