Answer: Chromatography
Step-by-step explanation:
Chromatography is the technique for separation of components in a mixture in a solution.
In the case of a separating RED and BLUE INK in a solution.
Prepare a MOBILE phase (gas or liquid), and a STATIONARY phase (liquid or solid), and OBSERVE the differences in the rates of migration of the RED and BLUE INK between the two phases during separation.