This is a recognisable pattern and it is good news: a light bar stuck on plain white, while the player number LEDs still work, is a fallback state rather than a hardware failure.
The two lighting systems are driven differently. The player number LEDs are simple on-off indicators controlled directly. The light bar is an RGB assembly that takes colour values, and those values come from whatever the controller is connected to. When the controller cannot get a colour instruction, or its stored lighting state has been lost, it falls back to a neutral default. White is that default. So a white light bar is the controller saying nobody has told me what colour to be, not the LEDs saying we are broken. Your player LEDs working confirms the board can still drive LEDs at all.
The usual triggers are a firmware update that reset the stored state, a hard reset, or a pairing record that has gone stale so the controller connects but never receives the lighting handshake. On PC specifically, it is also normal for the light bar to sit at a default colour because Windows sends no lighting instruction at all, which is worth ruling out: if it changes colour correctly on your PS5 but stays white on the PC, there is nothing wrong at all and that is simply how the controller behaves without software driving it.
So test on the console first. If it is white there too, do a controller reset with the pin hole, re-pair by cable, and the colour assignment usually returns immediately. If after that it is still white on the console, then the RGB driver on the board has failed, and that is a board-level repair that is not worth doing for a cosmetic feature on an otherwise perfect controller.
