The rendering pipeline always uses scRGB FP16 (DXGI_FORMAT_R16G16B16A16_FLOAT with DXGI_COLOR_SPACE_RGB_FULL_G10_NONE_P709). Linear floating-point preserves full HDR range and precision; scRGB covers the full BT.2020 gamut including negative values. DWM/ACM handles the final display conversion to whatever the connected monitor reports. There is no fixed built-in tone mapper in the render path — users build tone mappers as graph effects (e.g. via the D2D ColorMatrix/HdrToneMap/WhiteLevelAdjustment chain), which keeps full HDR accuracy on by default and avoids accidental clipping.