Since Colorado shops began legally selling marijuana in January 2014, traffic fatalities in the state have fallen, tax revenue has increased, and employment opportunities in a rapidly expanding industry have exploded.

That's the good news.

The bad news is that people of color are still being arrested for marijuana-related crimes at the same rates as before the law was passed, according to a report released on Wednesday by the Drug Policy Alliance, a national organization that promotes drug policies "grounded in science, compassion, health, and human rights," according to its website.

The Drug Policy Alliance reviewed drug arrests in Colorado's 64 counties two years before and two years after the passage in 2012 of Amendment 64, which legalized the possession, cultivation, and private use of cannabis within the state and provided for its commercial sale. The number of criminal charges for marijuana plummeted from more than 39,000 in 2011 to just over 2,000 in 2014.

Unfortunately, the report points out that racial disparities continue to persist in the state's drug law enforcement.Blacks are more often arrested for marijuana possession, distribution, and cultivation than white people.

"Black and brown communities have been the battlefield of the drug war," Art Way, the Drug Policy Alliance's Colorado director, told VICE News.

Amendment 64 states that people 21 and older can possess or purchase up to one ounce of marijuana at a time, and grow up to six plants at home in an "enclosed, locked space." Smoking or consuming marijuana in public remains illegal. Taking weed out of the state and driving under the influence of marijuana are also prohibited.

Data from the Colorado Bureau of Investigation shows that the arrest rate for whites for weed possession in 2010 was 335.12 per 100,000 people, while the arrest rate for blacks was 851.45 — 2.4 times higher. This imbalance was eerily consistent four years later: though arrests had declined, black people were still 2.4 times higher to be taken into custody for marijuana than white people. In both years, black people accounted for roughly four percent of the population, but more than nine percent of arrests for possession.

"The overall decrease in arrests, charges, and cases is enormously beneficial to communities of color who bore the brunt of marijuana prohibition prior to the passage of Amendment 64," Rosemary Harris Lytle, regional chair of the NAACP, said in a statement reacting to the report. "However, we are concerned with the rise in disparity for the charge of public consumption and challenge law enforcement to ensure this reality is not discriminatory in any manner."

Black people are more likely to be stopped, arrested, and prosecuted for violating drug laws despite the fact that whites and blacks consume marijuana at roughly the same rate. Someone is arrested in the United States for weed possession every 36 seconds — a black person is 3.73 times more likely to be arrested for possession than a white person.

Marijuana legalization "is a very important first step, but not a panacea," Sanho Tree, director of the Drug Policy Project, told VICE News. "No respected drug reformer has ever claimed that it would solve our problems in regard to race."