Place rack in middle of oven. Preheat oven to 350 degrees.
Grease and flour a bundt pan.
Combine buttermilk and lime juice in a small bowl and set aside.
In mixing bowl, cream butter and sugar until fluffy.
Add the eggs one at a time. Beat well to combine.
In another bowl combine flour, salt, baking soda and baking powder and stir to combine.
Add flour and buttermilk mixtures by alternating.
Add in food coloring and stir to combine. Add to desired shade of green.
Bake in prepared pan for 50-60 minutes. Test with a toothpick for doneness.
When done, let rest in pan for 20 minutes before inverting onto cooling rack.
To make glaze, combine powdered sugar and lime juice to a consistency thick enough to drizzle over cool cake. After drizzling, let cake set for 35 minutes before serving.