Summary blog excerpt text

I have just transformed from 7.0 to 7.1 and all is well except that the summary blog pages excerpt font is unreadable (faded out and not black) and I can't find where to go to change it. I have been using these summary pages live as my blog page because I didn't like the way the blog appeared in 7.0, but I need to be able to read the excerpt text. Thanks

https://www.susandeeley.com.au/lifestyleblog