Cooked something up, don’t burn yourself.
.sb-hashtag[data-tag-name="blue"]:has(.sb-highlight) + .sb-highlight,
.sb-hashtag[data-tag-name="blue"]:has(.sb-highlight, + .sb-highlight) > .sb-highlight,
.sb-hashtag[data-tag-name="blue"]:has(.sb-highlight) + .sb-highlight + .sb-meta.sb-highlight,
.sb-meta.sb-highlight:has(+ .sb-hashtag[data-tag-name="blue"]) {
background-color: blue !important;
}
.sb-hashtag[data-tag-name="blue"]:has(.sb-highlight) + .sb-highlight {
display:inline-block;
text-indent: -1ch;
}
.sb-hashtag[data-tag-name="blue"]:has(.sb-highlight, + .sb-highlight):not(:has( + .sb-highlight + .sb-highlight.sb-meta)) {
display: none;
}