Final answer:
Chromatography is not restricted to only coloured compounds. It can also be used to separate compounds based on differences in other physical properties such as polarity or size.
Step-by-step explanation:
Chromatography is not restricted to only coloured compounds. While it is commonly used to separate mixtures based on differences in color, it can also be used to separate compounds based on differences in other physical properties such as polarity or size. For example, in a process known as column chromatography, compounds are separated based on their affinity for the stationary phase. Compounds with a higher affinity will spend more time in the stationary phase, resulting in a longer retention time.