Android : Android How to save a picked color?

I use the Material Design Library from navasmdc [Library that i use][1]!I build in my app the colorselector.Now i want to save the selected color with sharedpreferences but i dont know how i can do that! I hope anybody can help me because that is an app project for school:

Menu_java

package com.studiocrew.lehrstellekontrolle;


import com.gc.materialdesign.views.ButtonFloatSmall;
import com.gc.materialdesign.views.LayoutRipple;
import com.gc.materialdesign.widgets.ColorSelector;
import com.gc.materialdesign.widgets.ColorSelector.OnColorSelectedListener;
import com.studiocrew.lehrstellekontrolle.R;
import com.nineoldandroids.view.ViewHelper;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.*;
import android.content.*;


public class Menu_java extends Activity implements OnColorSelectedListener{

    int backgroundColor = Color.parseColor("#1E88E5");
    ButtonFloatSmall buttonSelectColor;
    RelativeLayout rlE;

    @SuppressLint("NewApi")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.menu_layout);

        buttonSelectColor = (ButtonFloatSmall) findViewById(R.id.buttonColorSelector); 
        buttonSelectColor.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    ColorSelector colorSelector = new ColorSelector(Menu_java.this, backgroundColor, Menu_java.this);
                    colorSelector.show();
                }
            });

    }

    @Override
    public void onColorSelected(int color) {
        backgroundColor = color;
        buttonSelectColor.setBackgroundColor(color);
        findViewById(R.id.rlE).setBackgroundColor(color);
        findViewById(R.id.checkBox).setBackgroundColor(color);
        findViewById(R.id.view1).setBackgroundColor(color);
        findViewById(R.id.view2).setBackgroundColor(color);
        findViewById(R.id.view3).setBackgroundColor(color);

    }  
}

menu_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:materialdesign="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFF"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <RelativeLayout
            android:id="@+id/rlE"
            android:layout_width="fill_parent"
            android:layout_height="128dp"
            android:background="#01579b"
            android:paddingBottom="20dp"
            android:paddingLeft="104dp">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:text="Einstellungen"
                android:textColor="#FFF"
                android:textSize="25dp"
                android:layout_centerInParent="true"/>

        </RelativeLayout>


        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginLeft="24dp" >

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Notification" />

            <View
                android:id="@+id/view1"
                android:layout_width="fill_parent"
                android:layout_height="1dp"
                android:layout_alignParentBottom="true"
                android:background="#1E88E5" />
        </RelativeLayout>

        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="80dp"
            android:layout_marginLeft="24dp">

            <com.gc.materialdesign.views.CheckBox
                android:id="@+id/checkBox"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:background="#1E88E5" />

            <TextView
                android:layout_below="@+id/checkBox"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Stelle die Notificationen an oder aus." />

        </RelativeLayout>


        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginLeft="24dp" >

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Design" />

            <View
                android:id="@+id/view2"
                android:layout_width="fill_parent"
                android:layout_height="1dp"
                android:layout_alignParentBottom="true"
                android:background="#1E88E5" />
        </RelativeLayout>

        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="80dp"
            android:layout_marginLeft="24dp">

            <com.gc.materialdesign.views.ButtonFloatSmall
                android:id="@+id/buttonColorSelector"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="30dp"
                android:layout_centerInParent="true"
                android:background="#1E88E5"
                materialdesign:iconDrawable="@drawable/icn_select_color" />

            <TextView
                android:layout_below="@+id/buttonColorSelector"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Wechsle das Design der ganzen App." />
            <TextView
                android:id="@+id/sbtn"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Save" />
        </RelativeLayout>


        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginLeft="24dp" >

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Über" />

            <View
                android:id="@+id/view3"
                android:layout_width="fill_parent"
                android:layout_height="1dp"
                android:layout_alignParentBottom="true"
                android:background="#1E88E5" />
        </RelativeLayout>

        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="80dp"
            android:layout_marginLeft="24dp">

            <TextView
                android:id="@+id/tv1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Programmiert von: David Schor"/>

            <TextView
                android:layout_below="@+id/tv1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:text="Version: 1.3BETA"/>
        </RelativeLayout>

    </LinearLayout>

</LinearLayout>