One of the things about Carfax I like is you will learn where your vehicle spent it's life and also be able to fairly accurately verify mileage based upon title transfers and smog tests.
My 4Runner (one owner) also showed as being in an accident. I pulled the accident report and it said White 4Runner. Mine is and always has been gray metallic.
I got in touch with the original owner and he said the dealer they traded the vehicle in to also flagged that.
The vehicle has never been wrecked. Of that I am 100% sure after inspecting it with a fine tooth comb.