For my son's 3rd birthday, we had a "green" party. He loved green at the time and EVERYTHING had to be green. I made invitations to look like a green box of Crayons and printed the party specifics on the computer and glued it to the inside of the crayon box. I had every green decoration imaginable and several shades of green balloons everywhere. I purchased a cheap green t-shirt for my son and wrote "I am three" on it (he wore it all day!). As guests arrived, I handed out green beads and bandanas to wear. We then made green crowns from construction paper and glued all kinds of green jewels, etc on it. WE then played our version of "duck, duck, goose" but called it "blue, blue, green" ( I had a hard time convincing my son later that the game is ACTUALLY called duck, duck,goose..he always wanted to say blue, blue, green). We then had chicken nuggets with green ketchup, green grapes, kiwi, green beans and green punch. After opening gifts we enjoyed a homade green cake with green icing and sprinkles with some lime sherbert. My son loved that birthday and everyone talked about how unique the theme was.