This is doable, although a chore if you have a lot of tags that you want to change. You can get rid of the border sections if you just want the color. Just an example of what you can do.
/*---- reading view tag ----*/
.tag[href="#ObsidianClipperTest"] {
color: #ff0080;
background-color: inherit;
border: 1px solid #176bef;
line-height: 2em;
font-weight: 500;
padding-top: 1.5px;
padding-bottom: 3px;
}
/*---- source + live preview tag ----*/
.cm-tag-ObsidianClipperTest {
color: #ff0080;
background-color: inherit;
border-top: 1px solid #176bef;
border-bottom: 1px solid #176bef;
line-height: 2em;
font-weight: 500;
}
.cm-hashtag-begin.cm-tag-ObsidianClipperTest {
border-left: 1px solid #176bef;
padding-top: 1px;
padding-right: 1px;
padding-bottom: 3.5px;
}
.cm-hashtag-end.cm-tag-ObsidianClipperTest {
border-right: 1px solid #176bef;
padding-top: 1px;
padding-bottom: 3.5px;
}


This version from FireIsGood is a bit easier if you are doing multiple tags — you just need to change the tag colors parts at the bottom — but it’s still one-by-one.
/*---- tag formatting ----*/
.markdown-source-view .cm-hashtag {
background: var(--color-base-10);
color: var(--tag-color);
/*border-top: 2px solid;
border-bottom: 2px solid;*/
line-height: 2em;
font-weight: 500;
}
.markdown-source-view .cm-hashtag-begin {
/*border-left: 2px solid;*/
padding-top: 1px;
padding-right: 1px;
padding-bottom: 3.5px;
}
.markdown-source-view .cm-hashtag-end {
/*border-right: 2px solid;*/
padding-top: 1px;
padding-bottom: 3.5px;
}
.markdown-preview-view .tag {
background: var(--color-base-10);
color: var(--tag-color);
/*border: 2px solid;*/
line-height: 2em;
font-weight: 500;
}
/*---- tag colors ----*/
.cm-tag-ObsidianClipperTest, [href="#ObsidianClipperTest"] { --tag-color: #ff0080 }
.cm-tag-Personal, [href="#Personal"] { --tag-color: var(--color-red) }
.cm-tag-Important, [href="#Important"] { --tag-color: var(--color-green) }


Also, keep in mind that tags are case-sensitive; you may want to add [href="#Important"], [href="#important"], etc., to the rules. I was staring at it for a few seconds, wondering why it wasn’t working, before I realized my tag in the note was #important. ![]()