Night Stalker Richard Ramirez, who spent 24 years in prison after a spree of murders in California, died Friday, but not before turning a shocking shade of green.

The serial killer, who left satanic signs at murder scenes and mutilated victims’ bodies during a reign of terror in the 1980s, died reportedly after “sitting up in his bed doing stretches” just the day before at Marin County Hospital.

Richard Ramirez, 53, had been taken from San Quentin’s death row to a hospital where authorities said he died of liver failure, according to a source at the New York Post.

The source said  Richard Ramirez exhibited the ghastly-hued skin Thursday and was up and moving around his hospital bed.

“He was the color green,” said the Post‘s source.

“He looked like a green highlighter pen.”

Richard Ramirez had been housed on death row for decades and was awaiting execution, even though it has been years since anyone has been put to death in California. He was convicted in 1989 of 13 murders, five attempted murders, 11 s**ual assaults and 14 burglaries, which terrorized Southern California in 1984 and 1985. His charges included rape, so**my and o**l co****tion.

Though he died of liver failure, the exact cause of the ailment has not been released due to federal patient privacy laws.

At his first court appearance, Richard Ramirez raised a hand with a pentagram drawn on it and yelled: “Hail, Satan.”

Night Stalker Richard Ramirez had shockingly green skin the day before he died

His marathon trial, which ended in 1989, was a horror show. Courtroom observers wept when survivors of some of the attacks testified.

Richard Ramirez was finally run down and beaten in 1985 by residents of an East Los Angeles neighborhood while attempting a carjacking. They recognized him because his picture had appeared that day in the news media.

The trial of Richard Ramirez took a year, but the entire case which was bogged down in pretrial motions and appeals lasted four years, one of the longest criminal cases in U.S. history.

Because of the notoriety of the case, more than 1600 prospective jurors were called.

On his way to a jail bus, he sneered in reaction to the verdict, muttering: “Big deal. Death always went with the territory. See you in Disneyland.”

The black-clad killer, unrepentant to the end, made his comment in an underground garage after a jury recommended the death penalty for his gruesome crimes.

Inexplicably, Richard Ramirez, a native of El Paso, Texas, had a following of young women admirers who came to the courtroom regularly and sent him love notes.

Some visited him in prison, and in 1996 Richard Ramirez was married to 41-year-old freelance magazine editor Doreen Lioy in a visiting room at San Quentin prison.

Relatives called  Doreen Lioy a recluse who lived in a fantasy world.

In 2006, the California Supreme Court upheld Richard Ramirez’s convictions and death sentence. The U.S. Supreme Court refused in 2007 to review the convictions and sentence.

Two years later, San Francisco police said DNA linked Richard Ramirez to the April 10, 1984, killing of 9-year-old Mei Leung.

She was killed in the basement of a residential hotel in San Francisco’s Tenderloin neighborhood where she lived with her family.

Richard Ramirez had been staying at nearby hotels.

He previously was tied to killings in Northern California. He was charged in the shooting deaths of Peter Pan, 66, and his wife, Barbara, in 1985 just before his arrest in Los Angeles, but he was never tried in that case.