Found a "bug". At the bottom of question pages, in the dark bar, you've got the text 'Browse other questions tagged' and then the question tags get repeated. But these tags are white text on a white background. More specifically this CSS:
.bottom-notice .post-tag:not(.moderator-tag), .bottom-notice .required-tag:not(.moderator-tag)
{
color: white !important;
}
For some reason the regular color #999 gets overwritten by an !important
tag. On hover the text becomes readable, because the background turns red.
<kbd>
tags the other day but it fixed itself before I could post anything here. Not sure why though.