I have Website www.dinefreshconsultants.com

I have a Website https://www.dinefreshconsultants.com on the Home Page the Front Overlay Image that Dull Finishes how to adjust the Brightness in the CSS Section or This is the Problem can be solvable or not. Can anyone help out or solutions on this issue

 

In style.css look for:

.slide-content {
    background-color: rgba(0, 0, 0, 0.6);

Code (markup):

At line 521. That 0.6 is controlling the opacity of that background.

NOT that I'd recommend playing with that too much; any darker you won't see there's an image, any lighter you'll only further compromise the already questionable legibility of the white text being placed over the image... though a bit of text-shadow might be able to offset a lighter background.

That said, that site has PROBLEMS. Illegible colour contrasts, fixed metric fonts, absurdly undersized fonts all of which result in accessibility woes. Then the pointless redundancies, useless broken overstuffed TITLE and keywords that indicates black hat SEO scumbaggery GUARANTEED to get you pimp slapped clear off of search engines altogether... and that's before we talk the bloated train wreck that is the code. The home page has only 3k of plaintext, zero actual content images, and only one thing that even warrants the presence of MAYBE 8k of JavaScript at the high end, yet it is wasting 24k of markup to do likely not even half that's job, and the insane 4.49 megabytes of scripttardery. Don't get me started about the 728k of CSS across a dozen files when not one legitimate site of this nature has any need of more than 48k in one file per media target!

Which is to be expected when mental midgetry like bootcrap is involved. If you brought that to me as a client, my advice would be to pitch that entire mess in the trash and to start over from scratch. There is very little present worth salvaging apart from the copy.