Yes, you can absolutely have dyed hair at Disney World, whether you are a guest visiting the parks or a "Cast Member" working there. For guests, there are virtually no restrictions on hair color; you will see people with every shade of the rainbow, from neon pink to deep sea blue, especially since many fans enjoy "Disneybounding" or matching their hair to their favorite characters. Interestingly, the rules for employees (Cast Members) have also significantly relaxed in recent years. In 2021, Disney updated the "Disney Look" guidelines to be more inclusive and allow for "nontraditional" hair colors, provided they are well-maintained. This means your jungle cruise skipper or hotel concierge can now legally sport blue or purple hair as part of their professional appearance. As a visitor, your hair color is considered a form of personal expression, and as long as your overall attire remains family-friendly and doesn't involve a full character costume (which is prohibited for adults), you are free to enjoy the Magic Kingdom with whatever hair color you choose.