How to change the color of the search tab

Did you tried by modifying the Theme’s CSS (if has room for custom settings) to the button class?

i am using themify ultra theme.
i just need a css code to modify it.

Hi,
i am not exactly sure if this is what you want to do, but in order to change the gray search bar in [adverts_list] to green you can go to wp-admin / Appearance / Customize / Additional CSS panel and add there the code below

.adverts-options {
    background: green;
    color: white;
}

If this is not it, then it would be best if you can post a screenshot with the element which you want to modify marked.

here is the screenshot.
https://pasteboard.co/JobBvMZ.png
the code didnt work.

So you actually want to change the button color/background, not the search bar itself?

If so then in Additional CSS panel add the code below

a.adverts-form-submit.adverts-button-small {
    color: white;
    background: green;
}

if it will not work postfix the values with !important keyword like this color: white !important;.

Thanks, it did work.