Add a demo page with a custom SVG icon to wp-admin

svg-icon.php

<?php
/**
 * Plugin Name: SVG Icon Test
 * Description: Add a menu with an SVG icon to test the icon colorer
 */

add_action( 'admin_menu', function(){
	add_menu_page(
		'SVG Icon Test Page',
		'SVG Icon',
		'manage_options',
		'svg-icon',
		'__return_true',
		'data:image/svg+xml;base64,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',
		6
	);
} );