If you have a dedicated GPU, the setting is most likely to be on the on-board graphics card’ settings. This could be the NVIDIA Control Panel, the AMD Control Center, or the Intel Graphics Control Panel. The contrast and saturation is controlled by your graphics card therefore the setting to change contrast and saturation for your laptop display will be in your graphics card’s control panel. You can, the settings are just a little hard to find. Even the Settings app doesn’t offer you any options to change contrast and saturation for your laptop display. In contrast, you can only change your laptop display’s brightness and nothing else.
The brightness keys on your keyboard and Windows’ own brightness controls don’t control your monitor’s brightness. Stand-alone displays aka monitors have their own color controls.