What does the color of a "Epic Link" displayed in Confluence mean and how can I change it?

[Wolf Fisch]

I use the simple Jira filter on our Confluence pages to display some overviews of our Jira stories. When I chose the "Epic Link" column to be displayed, the different links are shown in different colours, i.e. the background of most of them is red, some are green and some are yellow. All links shown red are pointing to epics which are clones of one and the same epic - so maybe this is why they all have the same color. But what about the others, why does the color differ, what does it mean, and how may I change it? 

PS: It's not about the epic color that you change in the Jira board, that's something different and does not affect the color in Confluence. So I guess this is rather a Confluence than a Jira topic.

Versions:

Confluence 7.19.7

Jira v8.20.10