IfcOpenShell/src/ifcopenshell-python/ifcopenshell/api/style/add_style.py

class Usecase:
    def __init__(self, file, **settings):
        self.file = file
        self.settings = {
            "name": "Name",
            "surface_colour": [],  # RGB
            "diffuse_colour": [],  # RGB
            "transparency": 0,
            "external_definition": {"location": None, "identification": None, "name": "Name"},
        }
        for key, value in settings.items():
            self.settings[key] = value

    def execute(self):
        styles = [self.create_surface_style_rendering()]
        if self.settings["external_definition"]:
            styles.append(self.create_externally_defined_surface_style())
        # Name is filled out because Revit treats this incorrectly as the material name
        return self.file.createIfcSurfaceStyle(self.settings["name"], "BOTH", styles)

    def create_surface_style_rendering(self):
        return self.file.create_entity(
            "IfcSurfaceStyleRendering",
            **{
                "SurfaceColour": self.create_colour_rgb(self.settings["surface_colour"]),
                "Transparency": self.settings["transparency"],
                "ReflectanceMethod": "NOTDEFINED",
                "DiffuseColour": self.create_colour_rgb(self.settings["diffuse_colour"]),
            }
        )

    def create_externally_defined_surface_style(self):
        self.file.create_entity(
            "IfcExternallyDefinedSurfaceStyle",
            **{
                "Location": self.settings["location"],
                "Identification": self.settings["identification"],
                "Name": self.settings["name"],
            }
        )

    def create_colour_rgb(self, colour):
        return self.file.createIfcColourRgb(None, colour[0], colour[1], colour[2])