Are these two colours complementary

We often hear this question, either at the clothes shop or at a paint merchant. Either someone wants to know if the pink colour of a sweatshirt matches the mauve of a skirt, or perhaps a decorator needs to know if two shades of green will match when painted on opposing bedroom walls. 

But while asking questions concerning whether a series of colours are complementary, we are in fact asking two questions at once we ask about the colour in relation to how dark or light it is ( What is the brightness of the colour ) but we also ask a more subjective question, saying Is the pink more red or more white what kind of pink is it We are looking for two types of relationship. 

In any investigation, we first look for a qualitative relationship. In effect, we ask questions like, If I change the variable x, is there is a response in a different variable yV We look at what kind of response we can cause - a scientist wants to know about the qualities of the response, hence QUAL-itative. An obvious question relating to qualitative relationships is, If I mix solutions of A and B, does a reaction occur  

Only after we know whether or not there is a response (and of what general kind) does a physical chemist ask the next question, seeking a quantitative assessment. He asks, How much of the response is caused In effect, physical chemists want to know if the magnitude (or quantity) of a response is big, small or intermediate. We say we look for a QUANT-itative aspect of the relationship. An obvious question relating to quantitative relationships is, I now know that a reaction occurs when I mix solutions of A and B, but to what extent does the reaction occur what is the chemical yield  

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