Define defaults for Beaver Builder button module Link: https://pro.wpbeaverworld.com/add-default-colors-button-module/

functions.php

<?php

add_filter( 'fl_builder_settings_form_defaults', 'wpbw_default_color_button_module', 20, 2 );
function wpbw_default_color_button_module( $defaults, $type )
{
	if( $type == "button-module" )
	{
		$defaults->bg_color 		= "f59120";
		$defaults->bg_hover_color 	= "808080";
		$defaults->text_color 		= "ffffff";
		$defaults->text_hover_color = "ffffff";

		//* Border Settings
		$defaults->border = [
			'style' => "solid",
			'color' => "f59120",
			'width' => [
				'top' => '1',
				'right' => '1',
				'bottom' => '1',
				'left' => '1'
			]
		];

		$defaults->border_medium = [
			'style' => "solid",
			'color' => "f59120",
			'width' => [
				'top' => '1',
				'right' => '1',
				'bottom' => '1',
				'left' => '1'
			]
		];

		$defaults->border_responsive = [
			'style' => "solid",
			'color' => "f59120",
			'width' => [
				'top' => '1',
				'right' => '1',
				'bottom' => '1',
				'left' => '1'
			]
		];

		$defaults->border_hover_color = "808080";
	}

	return $defaults;
}