All funky colour plants ( from my own mistakes ) are very sensitive to ph swings. You grow one ...
I would worry more about plant state, not colour of bud. Especially when you grow purple strain.
There is plenty of time lapses on youtube. Enter : weed purple time lapse and you will see how colourfull strains by genetics develops...
Hello mate, your plant is a purple genetics that means if you have the right condition you will see the buds beginning purple now, they will are totally purple at the end.
Good luck and happy journey.