“But I don’t like the grey color of the Page font which I believe is coming from the Legacy css”
As mentioned earlier the archive widget uses the default font/color/size of the theme you are using (the body text). In other words, there isn’t anything in your css to point to for the archives because its not defined in your stylesheet. It references the default font in the body. If you switched themes it would use the default font of the body of that theme as well. You would have to create a style in your css specifically for the archive section.
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