It seems that no resource I come across addresses the fact that the pH range for phenolphthalein's color change is around 8.2-10. In other words, it's still colorless at 8.2. Why then, is it claimed that the indicator changes colors when the solution changes from an acid to a base? Wouldn't you want an indicator that changes colors at about pH 7?
If you analyse a titration curve you will immediately notice the pH shooting up near equivalence point. For this reason, there is very little difference to the amount of base added for pH 7 and pH 8 (due to the logarithmic nature of pH). So, it's not entirely accurate but certainly good enough (for strong acid - strong base and weak acid - strong base), if you want something better use an electronic pH tester