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.