Answer:
Shift in equilibrium position
Explanation:
The reddish-pink colour signalled the equivalence point. That is, pH=PKind. This was the point at which we have commonly the called the end point of the titration which has been carried out. As the solution was left to stand after this equivalence point was attained, the equilibrium position shifted again towards the acid side and the solution turned colourless once more. The equilibrium position indicated by the colour change depends on the H+ concentration of the solution.
