Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Color
OCIOSHADER_COLOR
Parameter: Linearize
OCIOSHADER_TRANSFORM_COLOR
Parameter: Texture
OCIOSHADER_TEXTURE
Parameter: Enable Color Management
OCIOSHADER_TRANSFORM_TEXTURE
Parameter: Multiplier
OCIOSHADER_MULTIPLIER
Parameter: Use Document Settings
OCIOSHADER_USE_DOCUMENT_SETTINGS
Parameter: Config
OCIOSHADER_CONFIG
Parameter: Input Color Space
OCIOSHADER_INPUT_COLORSPACE
Parameter: Output Color Space
OCIOSHADER_OUTPUT_COLORSPACE