You wouldnt be able to order or apply the hair if you wasnt great lengths certified, so yes.. and if you take a read about great lengths the hair is not coloured, im not 100% sure of the process but i do know they take great pride in the fact the hair is not coloured during the process. its all done in one big factory in italy; Rome.
i feel like ive started a major debate here lol, has anybody else not worked with great lengths? because it honestly speaks for itself.... check there website.. my boss has been to there factory and seen all the process but he is rather brief when it comes to descriptions!
and yes swimmin affects all human hair, which is why in the consultation you find out all about there lifestyle there job there hobbies etc.. i really wouldnt advise someone to have a full head if they were say a full time swimmer as it will dry the hair out, creating knots and eventually mattes which could end up ruining there own hair...