You might want to change the base green color of Fitzeous theme to match your brand. You can go to wp-admin/themeoptions/styling to change the base colors of theme.
On service block overlays, there is green color, you can change it by adding some custom css.Please enter below css in wp-admin/appearance/customise/additionalCSS box. ( Please change black color code #000000 below, to your desired color code.)
.service_row .body_mind .media:before { background-color: #000000; } .service_row .body_mind .media:hover:before, .service_row .body_mind .media:focus:before { opacity: .4; }