Changing colors on pop up Hints/ Previews

[nelsantiago]

So I've been working on a custom version of "Black Red" a child theme. It's darker than the original and I'm having problems tracking down the colors associated with the pop up hints/preview, see the image below. It looks like it's tied into some other CSS settings, SO I may need to add some code to the additionals file. But I don't know what to add. Any assitance would be appreciated.