Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Color
ID_LAYER_COLORParameter: Solo Mode
ID_LAYER_SOLOParameter: Viewport Visibility
ID_LAYER_VIEWParameter: Renderer Visibility
ID_LAYER_RENDERParameter: Manager Visibility
ID_LAYER_MANAGERParameter: Animation
ID_LAYER_ANIMATIONParameter: Generators
ID_LAYER_GENERATORSParameter: Deformers
ID_LAYER_DEFORMERSParameter: Expressions
ID_LAYER_EXPRESSIONSParameter: Locked
ID_LAYER_LOCKEDParameter: XRef
ID_LAYER_XREF