Theme Header Overlay annoyance

Hi Team, I a Feature Image, which has been built to blend into the body of the Site, but the Theme has a white overlay on the header which I cannot remove, Ive hunted through the forum to no avail. https://illumesocialclub.com/ The header image is supposed to blend in, but instead, stands out due to opaque white overlay on the image, and across alot of images ive added into the body also, can I remove these fade overlays for good?