Filter products on colour - by mart - on WordPress WooCommerce support

Hi

1) I recall having seen many of the X-store demo shops for woocommerce having an option to filter products on colour with an icon showing the colour. Now that I am setting up my own shop, I can’t seem to find any options that allows for that, nor is it mentioned in the docs. Can you please let me know how it is done? Thanks 🙂

2) How can I remove the currency symbool from all prices? I read somewhere that I should be able to do it by adding this to the functions.php file of the child theme:
//bellow removes currency symbol from all prices
add_action( ‘wpo_wcpdf_custom_styles’, ‘wpo_wcpdf_custom_styles’ );
function wpo_wcpdf_custom_styles () {
?>
.woocommerce-Price-currencySymbol {
display:none;
}