In order to study the neutralisation reaction of acid and base a student took `10mL` of dilite hydrochloric acid in a conical flask and added a few drops of phenolphthalein indicator to it. He then added dilute sodium hydroxide solution to the conical flask dropwise with a dropper while shaking the conical flask constantly. When the acid is comletely neutralised by the base, the solution in conical flask will turn: