Store product multiple colors to the database Laravel

I have a product table which has price, name, stock etc. and color_products table which has color_id, product_id. I want to store a product to the database with selected colors so far I'm getting an error Invalid argument supplied for foreach(). How can I fix this?

Controller

 $formInput=$request->all();   //If I do dd($formInput) I see all data

    $product = product::create(array_merge($formInput, [
        'user_id' => Auth::user()->id
    ]));
   
 // Insert color to the database

    $store_color = [];
    $colors = $request->color_id;

    foreach ($colors as $color) {
        $ouzColor = $color->save;
        $store_color[] = [
            'product_id' => $product->id,
            'color_id' =>  $ouzColor
        ];
    }
        ColorProduct::insert($store_color);

Blade file

  <select multiple name="color_id" id="color">
     <option value=""> --Select Colors -- </option>
         @foreach($colors as $color)
           <option value="" ></option>
         @endforeach
  </select>

via Chebli Mohamed