I’ve noticed a trend for adding jewelled pins being inserted into the flower heads of bouquets. Mostly the stems seem to be diamante – great for picking up the light – and pearl. I see no reason why you can’t add a variety of coloured gems to the flowers.
The Inspiration Box have several different varieties of crystal stems in colours including clear, amber, pink and burgandy for £2.99 (bunches of 12). Ask your florist for specialist jewels too.