Beat the eggs and sugar till fluffy. Gradually add oil/butter, vanilla essence and beat again for a min. (A)

Sift the flour and baking powder and add to (A) and mix.

Now divide your batter into equal quantity (I used equal size katoris or for measuring one can also use ice cream scoop spoon) depending on the number of colours you have ie. if you have 4 colors divide your batter equally into 4 different bowls.

Now in each bowl add a drop of color and mix well so u will have 4 (or more/less) bowls with 4 coloured (or more/less) batter.

Grease a baking dish with butter/oil and put butter paper /parchment paper at the base.

According to the colour combination you like take the first colour batter (say red) and put it in the greased baking dish. Pat your baking dish atleast ten times on your slab so that the colour batter (red) spreads evenly and there is no air in it.

Now Take the second colour batter (say blue) and put it on the first colour batter (red) already in the greased baking dish and pat hard on slab again so that the second colour (blue) spreads evenly on the first colour batter (red).

Repeat for as many colours.

Pre heat your oven at 200 c for 5 min and bake at 200 c for 30 min or until done.