Changing the Opacity of Column Images

Hi,

I’m wondering how to change the opacity of the column images. I have them set to display my latest post, showing the featured image with the post title. I want the titles to appear as “static on image”, but when I select that option the images in the columns appear really dark, and when hovered over turn almost black. I would like them to behave the same way, I just want them to appear as normal images and when hovered over to be slightly opaque.

I’ve searched through the CSS, and tried playing with a few things, but nothing seems to affect the images, only the title.

Is there anything I can adjust within the Nirvana settings? Any line of code that will affect the images themselves? Or anything I can add to the miscellaneous section of coding?

Thank you in advance for any help with this!

Cheers!

P.S. Sorry if any of this is newbie lingo, this is my very first attempt at creating a website 🙂