Cannot alter the very, very light – almost invisible color of some post labels

On all of my blog posts, the category, author, category, and Leave Comment text is nearly invisible. I have adjusted it countless times, and the text seems to darken when I save, but as soon as I close the control panel the text reverts to its original invisible self. Also, it's worth noting that whenever I adjust ANY color - border color, text color, link color - those fields darken. I am at my wit's end trying to resolve this; would love to get feedback on how to address. I've tried changing link color (the text is linked), tertiary text color, and all other text colors. If I start to change any other color, the author/category/leave comment buttons darken, but they don't change to the color I select (which I don't care about; I just want to readers to be able to see the text), and again - nothing I can do will save the changes to the color of this text once I close control settings side panel.