Thymol blue is a pH indicator which 3 colors according to the pH.
Thymol blue shows red color at below pH than 1.2 and shows yellow color at the pH between 2.8 and 8.0. For the pH above 9.6, thymol blue shows blue color.
Hence, the thymol blue has 2 pH ranges as 1.2 - 2.8 and 8.0 - 9.6.
Since, pH = 11 is above the pH = 9.6, thymol blue shows blue color.
You can look at the number of valence electrons and look at the size of the molecule itself to determine which element in this certain group is shown on the model.
