Discolouration of crown tooth and gums after 6 years? (Photos)

I've noticed my middle crown tooth is starting to be blue/purplish and my gums around the tooth is changing colour, I've never had a problem with it and i just noticed it changing colour recently, any idea what it could be? I won't have access to a dentist for the next 1 month as I'm working on a boat so I'm currently freaking out...

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