If 'AIR' is called 'GREEN', 'GREEN' is called 'BLUE', 'BLUE' is called 'SKY', 'SKY' is called 'YELLOW', 'YELLOW' is called 'WATER' and WATER' is called 'PINK', then what is the colour of clear sky ?

SKY

As, sky is of blue colour and according to the question, blue is called sky. Thus, the answer is "SKY".

In such types of questions, we need to stick to what is being asked in the question. The question asks the colour of the sky and the answer is blue, which is called as "SKY". Do not get confused that sky is called yellow and yellow is called water etc.