Preheat the oven for 10 minutes in 180°C. In a mixing bowl add melted butter , sugar , yoghurt and vanilla essence. Whisk very well for about 5 minutes.
In another bowl sieve flour , baking powder thrice. Combine dry ingredient into wet mixture laddle by laddle and mix.
Now add milk to make a smooth bater. Mean while preheat the pan for 45 minutes.
Now divide the batter in three parts. Add orange color and orange essence in one part and green color in other part.
Grease the tin with butter and sprinkle some flour; tap to remove extra flour. Now pour the orange batter then pour white batter, next pour gren batter. Repeat the process and tap twice to release air bubbles.
Now bake the cake for 35 minutes. When its done take the cake out and allow the cake to cool completely.
Now demould the cake, slice the cake and serve.