Select pie chart colors randomly

[e-caste]

Instead of having fixed colors, the pie charts could use some variety.
In particular, we need to keep the same color order (since it allows for a readable chart), but we can randomize the first color of the list (e.g. normally "Pink", "Blue", "Red" can also become "Blue", "Red", "Pink" and "Red", "Pink", "Blue", but never change order and become "Blue", "Pink", "Red").