Thanks for setting this up! I’m viewing the forum on an older screen and find the header text and icons hard to see with the default Discourse dark theme. I have a development version of Discourse on my computer. Playing around with that, adding this css to admin/customize/themes/{your_theme}/common/scss/edit
gives a better contrast.
.extra-info-wrapper .topic-link,
.d-header-icons .icon,
.extra-info-wrapper .badge-wrapper.bullet span.badge-category,
.d-header .title a,
.d-header .title a:visited {
color: #ddd;
}