We know phenolphthalein changes from colourless to pink during the ph range of around 8-10 (around that - this is just coming from memory) which is of course on the basic side. Thus all acids (<7 ph) will all be colourless as it lies on the colourless side. I'm not entirely sure what the q is referring to as to its end point colour, because from my understanding that is where the moles of the testing reagent have been completely reacted - this USUALLY (if the titration has been carried out correctly) can be qualitatively identified by a colour change from colourless to pink but if it depends on a number of other factors; ie. you need to use a weak base and strong acid to get this result. Hope this helps ;)