Hello, @naijapropertyhub,
Please watch this video: https://www.veed.io/view/dbd870ee-9754-4b77-b021-4fb878033f21?sharingWidget=true
In this video, I have shown you that there is no Vendor Info tab on the single product pages now, proof is shown in the video.
And regarding changing the sale price, I have done it for you on your site by creating a test product and showed in the video as well, you can delete that test product now after checking it on your site, you just have to change the color code for changing the color in that CSS code.
Regards 8Themes Team.