Need to change colour of the text in the all site

I have been reported by many users that the colour of the paragraph test is of a such light grey that is hardly readable…
how can I make it almost black?
The link is as follows:

Thanks in advance!

hey Umberto

Please add this CSS in appearance - customize - additional CSS

.front-page-section .section-header .section-description, #header .top-header .header-navigation ul .sub-menu li a, #services .section-content .service .service-entry, #latest-news .section-content .post .post-entry, #team .section-content .person .person-content p, #contact-us .section-content .contact-us-box .box-right span, #contact-us .section-content .contact-us-box .box-right span a, #contact-us .section-content .contact-us-social a, #contact-us .section-content .wpcf7-form p .wpcf7-text, #footer .copyright, #footer .copyright a, .widget table tbody, input, textarea, .markup-format h1, .markup-format h2, .markup-format h3, .markup-format h4, .markup-format h5, .markup-format h6, body {
color: #000000;

Colorlib Support Team