Returned to Blackness/ to revent to one's (evil) ways
It returned to its black color. Figuratively: it returned to the state it had been in before.
(He said: "My household does not accept me." He said to him: "What is her name?" "Hannah." "Beautify yourself, Hannah," and she became beautified. He said to him: "Now she is acting haughtily toward me." He said to him: "If so, let Hannah return to her blackness." And Hannah returned to her blackness" — Ta'anit 23b)
Translation
Expression (Hebrew)
חָזַר לְשַׁחְרוּרִיתוֹ
Definition (Hebrew)
חָזַר לְצִבְעוֹ הַשָּׁחֹר. בְּהַשְׁאָלָה: חָזַר לַמַּצָּב בּוֹ הָיָה קֹדֶם.
(אָמַר: לֹא מִיקְבְּלִי (מְקֻבָּלִים)עֲלֵי אִינָשֵׁי(אַנְשֵׁי) בֵּיתִי. -אָמַר לֵהּ:מָה שְׁמָהּ?- חַנָּה. (אָמַר) תִּתְיַפִּי חַנָּה, וּנְתִיָּפֶת (הִתְיַפְּתָה).-אָמַר לֵהּ: קָא מִגַּנְדְּרָא עֲלֵי (עַכְשָׁו הִיא מִתְנַשֵּׂאת עֲלֵי).-אָמַר לֵהּ: אִי הֲכִי (אִם כָּךְ) תַּחֲזֹר חַנָּה לְשַׁחְרוּרִיתָהּ. וְחָזְרָה חַנָּה לְשַׁחְרוּרִיתָהּ"- תַּעֲנִית כג ע"ב)