react-native-charts-wrapper/android/src/main/res/drawable-nodpi/circle_marker.xml

A react-native charts support both android and iOS.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid android:color="#454545"/>
    <stroke
        android:width="2dp"
        android:color="#fff"/>
</shape>