Visited tags and badges are styled differently to unvisited ones

Question

I just recently (some two weeks ago) noticed that on some sites (certainly Movies & TV and Seasoned Advice, even if harder to notice there) the font color inside the tags behaves like links, which means the font color is the normal one when the corresponding link (i.e. the respective tag page) has not been visited yet. But once you click/visit that tag, it turns into the color for visited links. This happens on the main site and on meta and seems to be a very recent "feature" (i.e. newer than the profile page update, I'd say).

Now first of all, I'd like to know if this is a feature at all or just a bug somehwere in the style sheet or whatever. Or maybe this just happens to me (on Firefox 38.0.1), though, comments and chat indicate it doesn't.

If it is actually supposed to be a feature, though, then I would strongly question its validity, since it doesn't seem to be relevant if one has ever visited a tag's page and it just results in an inconsistent design for tags which suggests a semantic difference between the tags where there is none. It also seems to rob the tags of the nice design contrast their color provides to the rest of the sites' font colors.

The same bug/feature seems to apply to those little light grey "modified/answered/asked X hours ago" thingies under the question title in the questions list, too. And as it is for tags, this different coloring is equally unnecessary and distracting there, too. And also the same for the badges shown in the profile:

_{I actually asked this question on a per-site meta already but since it didn't seem to get any attention from the responsible powers there and actually applies to more than one site, I figured I'd rather try my luck here.}

Answer 1

As per the latest reply from Kurtis Beavers, on the meta from Movies & TV:-

Pushed a fix earlier today. Should be good now. - Kurtis Beavers

It was not disclosed how but its fixed now.

Answer 2

This is a .css feature which can be coded with :visited appended to the anchor.

Consider the css styling below

/* unvisited link */
a:link {
    color: blue;
}

/* visited link */
a:visited {
    color: red;
}

/* mouse over link */
a:hover {
    color: green;
}

/* selected link */
a:active {
    color: yellow;
}

One can incorporate different properties to the anchors just like this.

For me, this is very valid and we can also see this feature in Google, you can see color change in search result after clicking one of its link (link color changes from blue to violet). Though it won't work if you open the link in new tab.

In the end, the design is totally dependent on designer/html developer, it can look good or bad depending on the style chosen.

Below is what I see in my computer. There is a definite change in the color of visited links and tags but that is not seem that off. It was a deliberate attempt as I checked the color from developer console where visited style is given

.question-hyperlink:visited, .answer-hyperlink:visited, #hot-network-questions ul a:visited {
  color: #1e6872;
}