code perfect

app/src/main/java/com/mxdl/customview/test/ScrollTestActivity.java

@@ -25,7 +25,7 @@ public class ScrollTestActivity extends AppCompatActivity {
         mBtnScroll.setOnClickListener(new View.OnClickListener(){
             @Override
             public void onClick(View v) {
-                mTxtScroll.scrollBy(-200,-200);
+                mTxtScroll.scrollBy(200,200);
             }
         });
 

app/src/main/java/com/mxdl/customview/test/ViewPagerTestActivity.java

@@ -12,7 +12,7 @@ import com.mxdl.customview.test.view.MyViewPager;
 public class ViewPagerTestActivity extends AppCompatActivity {
 
     private MyViewPager mViewPager;
-    int[] colors = {Color.BLACK,Color.GREEN,Color.BLUE};
+    int[] colors = {Color.GREEN,Color.RED,Color.BLUE};
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);