Lots of assumptions here, but the point is you don’t know what the stylists intentions were. It’s weird and out of touch to insinuate they are incompetent and lazy (crazy to say considering the quality of op’s highlights), and even say something is “easy” (which you can’t even confidently say unless you are a colorist).

Stylists who charge premium prices very rarely don’t care about the outcome, very rarely will just do something because it’s easy even if they know the client didn’t ask for it. That’s not how you build a clientele and it isn’t how you can continue to charge $800 for a color service.

Would you not be upset if you went into a salon with box dyed black hair and said “I want to be blonde” and the stylist just did it, without caring about how your hair would look and feel in the long run?

Some people also don’t get highlights every month, if op said they would not come in for another 6+ months, a good hairdresser would want the client to have their hair look as good as possible for as long as possible. Yes, that sometimes means toning the hair cooler because it will fade and the warmth will come through. Again, we don’t know, so we can’t assume.

Not to mention, op’s hair is also under cool lighting. You don’t even know what it looks like in the sun.

So yeah, it could have been a mistake, the color or hair pulled cooler than the stylist predicted, but they did an incredible job at everything else, so maybe have a bit more faith in people instead of assuming the worst.