Darken Grayscale in PDF

[Masha26763820d54g]

We have a PDF that I need to darken the paragraph shading. The text is already at 100% black and the background is 100% white and we want to keep that. I just want to change (darken) the other elements. Is there a way to do that through a Preflight action or a way to customize a preflight action? Sample page from PDF attached.

[Luke Jennings3]

Yes, you can change a specific color with a preflight fixup, here is a link to a related discussion with instructions:

https://community.adobe.com/t5/acrobat-discussions/how-do-i-make-colored-text-black-for-press/m-p/92...