def METHOD_NAME(self, background_data, factor):
    new_channels = []
    for max_factor, band_name in zip(self.max_factor, "RGBA"):
        new_channel = background_data.sel(bands=[band_name])
        if max_factor != 0 or max_factor is not None:
            new_channel = new_channel + factor * max_factor
        new_channels.append(new_channel)
    return new_channels