public class MainActivity extends AppCompatActivity {

    TextView textView1,textView2,textView3,textView4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ArrayList<Integer> list = new ArrayList<>();
        list.add(Color.parseColor("#ff1744"));
        list.add(Color.parseColor("#4a148c"));
        list.add(Color.parseColor("#1a237e"));
        list.add(Color.parseColor("#00bcd4"));
        list.add(Color.parseColor("#4caf50"));
        list.add(Color.parseColor("#ffc107"));
        list.add(Color.DKGRAY);
        list.add(Color.YELLOW);
        list.add(Color.MAGENTA);
        list.add(Color.CYAN);

        textView1 = (TextView) findViewById(R.id.textView1);
        textView2= (TextView) findViewById(R.id.textView2);
        textView3 = (TextView) findViewById(R.id.textView3);
        textView4 = (TextView) findViewById(R.id.textView4);

        final Random random = new Random();

        textView1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                    int color2 = random.nextInt(10);
                    int color3 = random.nextInt(10);
                    int color4 = random.nextInt(10);
                    if (color2 == color3 || color2 == color4 || color3 == color4){
                        color2 = random.nextInt(10);
                        color3 = random.nextInt(10);
                        color4 = random.nextInt(10);
                    }
                    textView2.setBackgroundColor(list.get(color2));
                    textView3.setBackgroundColor(list.get(color3));
                    textView4.setBackgroundColor(list.get(color4));

            }
        });
    }
}