Green
Red mixed with a little water will make a pink color. If you are making icing, add a drop of two of red food coloring to white icing in order to turn the icing pink.
The colours which are required to create green are blue and yellow, so technically you cannot create green from pink as pink is created from red and white, as adding blue and yellow to red would create brown or black. However, if you add a surplus amount of blue and green to pink icing, it should eventually become green if the amounts of blue and yellow out weight the amount of red dye used.
To create kelly green icing, you would typically mix equal parts of blue and yellow food coloring. Start with a base of white icing, then gradually add the blue and yellow until you achieve the desired shade of kelly green. Adjust the mixture as needed to reach the perfect balance between the two colors.
Royal Icing is not a brand of icing to be purchased. It is made by using a recipe. It dries to a hard white, shiny gloss. Adding food coloring will make different colors.
black, of course
by adding orange food coloring to white icing
Using white icing you will have to add blue food coloring to it.
brown food coloring
The leaves are still able to make food even if they are colors other than green.
The colors blue and yellow combine to make the color green.
Use more food coloring
dark green and white or yellow and blue