Gutenberg custom blog style

functions.php

<?php

add_action('init', 'jurs_register_block_styles');

function jurs_register_block_styles() {
    register_block_style('core/paragraph', array(
        'name'         => 'lead',
        'label'        => __('Leading Paragraph', 'themeslug'),
        'inline_style' => '.is-style-lead {
            font-weight: bold;
            font-size: 1.15em;
            color: #333628;
		}'
    ));
}

?>