Electric vehicle maker Tesla has mislabeled and under-counted workers' injuries to make its safety record look better than it was, according to a new investigative report by RevealNews.org.

"Company officials labeled toxic exposures, muscle strains and repetitive stress injuries as personal medical issues or minor accidents requiring only first aid, lowering its official injury count," said the report.

Sources told Reveal that safety compromises were made at Tesla's Fremont factory to appease CEO Elon Musk's aesthetic preferences.

According to them, because Musk didn't like the color yellow, the factory floor did not have clearly marked pedestrian lanes, and instead had lanes painted different shades of gray. Tesla employs thousands of workers in Fremont where it makes its Model S, Model X and Model 3 vehicles.

Tesla, which has been under pressure to ramp up the production and delivery of its Model 3 electric sedan, disputed each of Reveal's findings in the report, including with a company blog post on Monday.

Tesla Chief People Officer Gaby Toledano, and its Vice President for Environment, Health and Safety, Laurie Shelby, gave interviews to Reveal suggesting that any past safety problems at the company have been resolved through a mix of employee training programs and process improvements. Shelby said she was confident the company was accurate in its reporting of worker injuries.

As part of this investigation, reporters Will Evans and Alyssa Jeong Perry spent months collecting and evaluating Occupational Safety and Health Administration injury and illness records, as well as workers' compensation, fire and 911 call records.

Dozens of current and former Fremont factory workers, including safety experts, were interviewed, and internal Tesla records obtained from sources.

Musk tweeted on Friday, "Excessive automation at Tesla was a mistake. To be precise, my mistake. Humans are underrated."

Read the full Reveal report here.