It's appropriate that the NFL's "Rivalries" uniform rollout for the 2025 season will conclude with one of the league's fiercest set of foes meeting in a high-stakes Week 18 matchup in prime time.

The San Francisco 49ers will be the eighth team to utilize their new alternates Saturday night when they don the "For the Faithful" threads against the Seattle Seahawks when the squads clash at Levi's Stadium with the NFC West title and conference's No. 1 playoff seed on the line. It will mark the first time the Niners have worn black jerseys in eight years, though the new ones should pop in a way the simpler black-and-red ones they occasionally used between 2015 and 2017 did.

The 49ers are asking their fans − alternately known as the "Faithful" − to wear black.

For the first time, the Niners will be in monochrome black as they also wear black helmets − which they've never had since joining the NFL in 1950. The dome is matte black, adorned with a pair of red stripes down the centerline, the familiar interlocking "SF" logo and gold-coated facemasks intended to sparkle under Levi's Stadium's lights. "Faithful" is scripted on the headgear's back bumper.

The red jersey numbers are outlined in gold and presented in a saloon-like font derived by the franchise's classic wordmark. A cursive "Faithful" is etched above the numbers on the chest, enabling the franchise to express its "steadfast appreciation for the unwavering dedication of 49ers fans across the globe." “Faithful to the Bay," the club motto, is stitched inside the collar. Per Nike, the look is "inspired by the Gold Rush era that once defined San Francisco."