Nothing, birds shed old feathers regulary to maintain their plumage. That is all.
It means that you have plucked a feather that is grey out of the air! It is now in your possession!
I have found white and also gray feathers. I believed the white were from angels but was concerned about the gray. I am aborn-again christian and experience many signs and wonders and believed the feathers were a sing from Godre-afirming me that He was with me and loved me.
When you find a crow feather, it represents good health and staying away from harsh cancers and diseases.
Gray feathers in the spirit world are often associated with neutrality, balance, and wisdom. They may signify that you are being guided to find harmony and clarity in your thoughts and emotions, and to approach situations with a sense of calm and understanding. Trust in the messages that the gray feathers are bringing to you from the spiritual realm.
There was/is a cardinal nearby
There are Angels in your life
The blue feather is what you use to purpose to the person you like when they have a red heart.
It means a bird was just flying by and dropped a feather no omen no sign just simple as that :)
it means you will have good luvck for 100 days
it means its bad luck.
The death of your loved one is ambiguois
Finding a cardinal's feather has no significance other that the pleasure of finding such a pretty thing. There is nothing supernatural involved.