Changing the colors on Lightbox Forms

Hello, I have a sage green color for all my buttons throughout the site EXCEPT on the Services Page for the Buyer's Guide. There it has made the button black. I implemented the code below to change it but for some reason it will change the hover color but not the background of the button when it's "inactive". I would like the background and hover color to be the same as the other buttons on the site.

I'd also like these same colors to be applied to the "Submit" button of the lightbox form itself and to have it look the same (font, spacing) as the other buttons.

#B1C7B4 is the Sage Green color of the "inactive" buttons.
I am not sure what the light green hover color is from the other buttons.

Help would be much appreciated!

Site: https://krill-panda-563t.squarespace.com/

Password: 0penthevidor

.sqs-block-content .lightbox-handle {
 color: #FFF;
 font-weight: 400;
 background: #0099FF;
}
.sqs-block-content .lightbox-handle:hover {
 color: #000;
 font-weight: 400;
 background: #B1C7B4;
}

Hi,

Where is lightbox form?

On the Services Page there is a button "Get Our Buyer's Guide" - this opens the Lightbox Form. The button that is black that turns green is what I am referring to and then the "Submit" button on the form once it's open.