Dyeing flowers is a popular way to create colorful floral arrangements, and carnations are among the easiest to alter. Using safe, nontoxic food coloring to dye the petals produces the desired effect with ease. To dye carnations green, begin with white flowers because they take color faster and more easily than other types. Purchase the flowers from a florist's shop or harvest them fresh from the garden. Just make sure each flower has a long, undamaged stem to carry the green dye to the petals.
Cut about 2 inches from the bottom of each stem with a sharp kitchen knife. This leaves an open wound that allows the dye to penetrate more easily. Set the carnations aside while you prepare the dye solution.
Add the green food coloring to 1 pint of warm water in a glass jar. Stir thoroughly until the food coloring is completely dissolved. Add the granulated sugar and stir again to dissolve.
Transfer the green dye solution to smaller glass vases, one for each carnation. Add about 3 inches of the solution to each vase.
Place each carnation into a vase with the stem immersed in the dye. Allow the flowers to remain until they have the shade of green you want. For dark green carnations, this could take up to 24 hours.
Remove the green carnations once they're dyed to your liking. Wash the ends of the stems to remove any excess dye before using the flowers in floral arrangements or bouquets.