More than 3,000 decades-old warrants for low-level marijuana offenses were purged Wednesday — part of an ongoing push to give New Yorkers of color a fresh start.

The bench warrants, dating back to 1978, were formally vacated by Manhattan District Attorney Cy Vance at a hearing in Manhattan Criminal Court.

“By dismissing these cases, we’re removing all of the collateral consequences — for one’s job prospects, school attendance, housing applications and immigration status — associated with an open criminal court case,” Vance told Justice Kevin McGrath. “And in doing so, we’re taking one small step toward addressing the decades of racial disparities behind the enforcement of marijuana in New York City.”

In total, 3,042 warrants were tossed and sealed — cases that included 79 percent of New Yorkers of color, 46 percent of whom were 25 years old or younger at the time of their arrest, officials said.

Last month, Vance’s office stopped prosecuting low-level pot possession and smoking cases, an initiative expected to lower prosecutions by 96 percent, from about 5,000 a year to fewer than 200.

Exceptions to the policy include those in possession of large quantities of marijuana, such as dealers, and defendants who are under investigation for a violent crime.

A similar en masse dismissal is in the works in Brooklyn. Last week, DA Eric Gonzalez announced plans to clear 3,438 warrants on marijuana offenses issued before Sept. 1, 2018 — and will offer people with marijuana convictions a chance to have them expunged from their records.

Vance said he’s looking into whether his office can “legally expunge” old convictions, too.

The NYPD has also taken a more lax approach toward tokers. Cops recently began issuing summonses to pot smokers and those in possession of small amounts, instead of arresting them.