Some display adapters support downloadable gamma correction tables. These tables let you control the colors generated by the digital-to-analog converter (DAC) by mapping specific RGB values to DAC values. You can set the gamma ramp for any 24-bit display adapters that provide hardware gamma correction by using the SetDeviceGammaRamp function. The hardware gamma ramp is a global property that affects all running applications and is not changed on a per-device context basis. You can retrieve the current gamma ramp by using the GetDeviceGammaRamp function.