Blue doors indicate a place where evil lurks. It is most often a secret communication to other evil-doers, informing them it is one of their establishments. Any number of evil rituals happen in these establishments in secret (ie: after hours, hidden rooms, etc)
“Oh look Hillary, that bar has blue doors.”

“Duh, Bill, we’re having pizza with walnut sauce there tonight with Marina and John!”

“Yum! Hopefully hotdogs with maps too!”
by bbnico June 15, 2019
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Often inhabited by Criminals and Scumbags
Dude 1: "I saw a guy getting arrested in his blue doored house the other day"
Dude 2: "What a scumbag"
by Herrothere123 July 1, 2010
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A scummy child, teenager or young adult that lives in a council house. This name is apparent as most council houses have blue doors.

Blue Door Kids are often a nuisance and just make the place look untidy in their tracksuits.
Person 1: Wow! What a fucking chav!

Person 2: Yeah; complete Blue Door Kid.
by that.kid.over.there February 27, 2011
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