Hi there!
Thanks for reaching out.
If you want to change the color of that underline for only the My blog and contact me title, then you can use the following code in your custom CSS:
.title.center h3:before {
background-color: red !important;
}
Put your own color in the above code instead red.
If you want to get rid of that underline style from everywhere in your pages, then you can try this:
.page-item.active .page-link, .sp-simpleportfolio .sp-simpleportfolio-filter > ul > li.active > a, .slider-item .sppb-btn-success, .sp-simpleportfolio .sp-simpleportfolio-item .sp-simpleportfolio-info:hover, .sp-simpleportfolio .sp-simpleportfolio-item .sp-simpleportfolio-overlay-wrapper .sp-simpleportfolio-overlay, .slider-btn a:hover, .intro-item .sppb-media-content, .about-colum, .title h3:before, .counter, .skills .skill .skill-bar span{
display:none;
}
Here is all about custom code placement in Helix Ultimate framework:
https://www.joomshaper.com/documentation/helix-framework/custom-code-css-js-meta
Best regards,