Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Color
FIRESHADER_COLORParameter: U Frequency
FIRESHADER_SCALEXParameter: V Frequency
FIRESHADER_SCALEYParameter: T Frequency
FIRESHADER_FREQUENCYParameter: Turbulence
FIRESHADER_TURBULENCE