As per the Constitution of India what is the essence of the Doctrine of Colourable Legislation?

It implies that when a legislature cannot achieve something directly within constitutional limits, it cannot achieve it indirectly either, Explanation: The Doctrine of Colourable Legislation is founded on the Latin maxim “Quando aliquid prohibetur ex directo, prohibetur et per obliquum” which states that whatever  is unable to be done directly, cannot also be done indirectly. The doctrine of colourability is the idea that when a legislature wants to do something that it cannot do within the constraints of the Constitution, it colours the law with a substitute purpose, allowing it to accomplish its original goal. The scope of the doctrine is well-explained by the Supreme Court in the matter of K.C Gajapati Narayan Deo vs. State of Orissa 1953.