>> PHOTOS: Steelers RB DeAngelo Williams wearing pink

He asked the NFL for permission to wear pink throughout the season, not just during October, to honor his mother. NFL vice president of football operations Troy Vincent denied his request, ESPN reported.

Williams told ESPN on Monday night that Vincent told him there are no exceptions to the uniform policy.

"He told me no. I'm assuming they are telling everybody else no as well. ... It wasn't about selling it. You know and I know and everybody else knows before I made the phone call," Williams said, according to ESPN.

Instead, Williams has dyed the tips of his hair pink.

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Despite the setback, Williams partnered with Charlotte Radiology last December to pay for mammograms for 53 women – his mother’s age when she died – at a hospital in Charlotte, North Carolina. One of the women tested was diagnosed with cancer.

Williams posted this to his Facebook page:

"Charlotte Radiology & my foundation partnered to provide 53 mammograms for low income or under-insured women, which we called '53 Strong for Sandra' in memory of the 53 years my Mom lived. ‪#‎MammogramsSavesLives."

His foundation has reached out to Charlotte Radiology to talk about potentially doing the campaign again during the off-season in Charlotte and Pittsburgh, but there is nothing formally scheduled.

Williams told ESPN's Lisa Salters, "It's not just about October for me. I's not just a month; it's a lifestyle. It's about getting women to recognize to get tested."

>> Click here to see his Facebook post