Black creatures in general are more prone to become possessed by Jinn.
Which hadith says that?
I don't recall. Perhaps it was from a fatwa, or "Ibn Taymiyyah's essay on the Jinn". Something about black being a color that preserves and attracts heat, being advantageous for Jinn, who are made from fire.
Then why on earth were they constantly telling us women to wear black or that black is the best colour?
Saudi women, who always wear black,
are sometimes possessed by jinns!
Fawza Falih Muhammad Ali is a Saudi woman who made international headlines after she was condemned to death for practicing witchcraft in 2006.[1] As of August 2008, she was still facing execution.[2]
In a letter dated February 13, 2008, Christoph Wilcke, a researcher with Human Rights Watch, exhorted King Abdullah bin Abdul Aziz Al Saud to halt her execution. The letter states she was sentenced to death by beheading for the crimes of witchcraft, recourse to jinn, and animal slaughter. Human Rights Watch argued that Falih should not be executed because the crime of witchcraft is not defined by Saudi law, the judges failed to ensure a fair trial, and Falih was unable to defend herself because of "significant procedural flaws throughout the trial".[3