Hairstylist's advice?

So I'm allergic to hair dye. But I have really long hair and want to do a light blonde ombré colour. I was told the dye never touches my scalp but the toner does. Some say the toner will be a problem because of the allergy & others say I'll be fine. And not many people in my town know what they are talking about when it comes to hair and stuff so idk 🙈 lol