Hook to change map colors for my Beaver plugin.https://github.com/thierrypigot/beaver-builder-googlemaps

functions.php

function tpbbgmap_custom_map_style( $map_style ) {
    $map_style = '[{"featureType":"water","elementType":"geometry","stylers":[{"color":"#e9e9e9"},{"lightness":17}]},{"featureType":"landscape","elementType":"geometry","stylers":[{"color":"#f5f5f5"},{"lightness":20}]},{"featureType":"road.highway","elementType":"geometry.fill","stylers":[{"color":"#ffffff"},{"lightness":17}]},{"featureType":"road.highway","elementType":"geometry.stroke","stylers":[{"color":"#ffffff"},{"lightness":29},{"weight":0.2}]},{"featureType":"road.arterial","elementType":"geometry","stylers":[{"color":"#ffffff"},{"lightness":18}]},{"featureType":"road.local","elementType":"geometry","stylers":[{"color":"#ffffff"},{"lightness":16}]},{"featureType":"poi","elementType":"geometry","stylers":[{"color":"#f5f5f5"},{"lightness":21}]},{"featureType":"poi.park","elementType":"geometry","stylers":[{"color":"#dedede"},{"lightness":21}]},{"elementType":"labels.text.stroke","stylers":[{"visibility":"on"},{"color":"#ffffff"},{"lightness":16}]},{"elementType":"labels.text.fill","stylers":[{"saturation":36},{"color":"#333333"},{"lightness":40}]},{"elementType":"labels.icon","stylers":[{"visibility":"off"}]},{"featureType":"transit","elementType":"geometry","stylers":[{"color":"#f2f2f2"},{"lightness":19}]},{"featureType":"administrative","elementType":"geometry.fill","stylers":[{"color":"#fefefe"},{"lightness":20}]},{"featureType":"administrative","elementType":"geometry.stroke","stylers":[{"color":"#fefefe"},{"lightness":17},{"weight":1.2}]}]';

    return $map_style;
}
add_filter( 'bbgmap_map_style', 'tpbbgmap_custom_map_style' );