<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="cl.cutiko.diadelpicoapp.ui.LoginActivity_">

    <!-- This is an Activity example -->
    <!-- Here im using the style to get the custom_pb but you could also simple use the background property and reference it -->
    <ProgressBar
        style="@style/custom_pb">
    </ProgressBar>


</RelativeLayout>

/*Or just add this in your Activity*/

loginPb.getIndeterminateDrawable().setColorFilter(getResources().getColor(R.color.cta_third), PorterDuff.Mode.SRC_IN);

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:pivotX="50%" android:pivotY="50%" android:fromDegrees="0"
    android:toDegrees="360">
    <shape android:shape="ring" android:innerRadiusRatio="3"
        android:thicknessRatio="8" android:useLevel="false">

        <size android:width="100dp" android:height="100dp" />
        <gradient android:type="sweep" android:useLevel="false"
            android:startColor="@color/cta_main"
            android:endColor="@color/cta_third"
            android:angle="0"
            />
    </shape>
</rotate>

<!-- Im using colors here taken from the color.xml file, create your own there or just use a hex color in place -->

<resources>

  <!-- Dont need to copy this entire file just copy this in your style -->
  <!-- see how custom_pb is reference for the background -->
  
  <style name="custom_pb">
    <item name="android:layout_width">100dp</item>
    <item name="android:layout_height">100dp</item>
    <item name="android:layout_gravity">center_horizontal</item>
    <item name="android:background">@drawable/custom_pb</item>
    <item name="android:indeterminate">true</item>
  </style>
  
</resources>