Answer :
The correct answer is no color will observed if a pure substance is analyzed ,
Chromatography :
It is a technique commonly used to separate a mixture of chemical substances based on their affinity with stationary phase and mobile phase .
The mobile phase travels through the stationary phase in a definite direction . The component of mixture travels along with mobile according to their affinity , ionic interactions , diffusion , solubility on stationary phase .
The component has more affinity with mobile phase goes higher with mobile phase .
While component with stationary phase remain at lower position on stationary phase .
This is how separation of components takes place.
A pure substance has only one type of component in it . There is no mixture of components.
Hence when pure substance will be analyzed by chromatography technique, there will be no separation of components .
So there will no color be observed.