blue chamber

From the tale of Bluebeard.

• "“[…] Matty would scarcely find fault with my visiting their blue chamber. […]”"
• "On Sundays, Miss Pross dined at the Doctor’s table, but on other days persisted in taking her meals, at unknown periods, either in the lower regions, or in her own room on the second floor—a blue chamber, to which no one but her Ladybird ever gained admittance."
• "My mother dared not break the lock, as my father had prohibited any one from entering this, his blue chamber; and what was worse, he had the key."