I've had stylists tell me this in the past, that it apparently makes it harder for it to take the color they're trying to do, but I'm too scared to get mine professionally done until there's a vaccine that's proven to be effective and I have too much gray to let it go, even working from home, I occasionally have Teams meetings where we have to be on video so I do my own and when I do get it done professionally again they'll just have to deal with it.