Gray overlay issue on images

Hi there!

I’m having a lot of trouble removing the gray overlay on the images on my blog posts and on the landing page. I’ve contacted my theme developer but she let me know that this is not an issue with the theme, but a wodpress issue.

If you look at the images in the link – the first images (featured image) is shown in the correct color scheme, but the images below the title that I’ve inserted in the actual post have a gray overlay.

Can you please let me know how I can fix this issue?

Best,
Tiffanie

The page I need help with: [log in to see the link]