There isn’t much available and I am still searching, but for those who might be interested here is what I have found so far.
Signs and Symbols: fish, horses, seagulls, amber, gold, rivers, holy stones, the four elements, crowns, keys
Colors: Blue, white, silver, green
Myths: The Birth of Dagda, Tuatha de Danann
Encyclopedia of Celtic Mythology and Folklore
Celtic Myth and Mythology Edain Mccoy
Celtic Magic dj conway
I know there are a lot of links. I’m not writing a research paper but I need to give credit…Mother Danu Does Not Approve of plagiarism! Hope this is useful, as there is some good info even if it isn’t a lot.