There is nothing Brave can technically do about the dark mode, that comes from Chromium code. Also, it is automatic, the only one that can fix it is Lowes web developers who can give compatibility to it.
You could go to chrome://flags/#enable-force-dark and try different modes. I use CIELAB but inversion of non-image elements does the same job, and it is the better one, but it won’t fix the problems at lowes, because what happens is exactly the same than other pages that have issues with automatic dark mode, the page has CSS properties that are bad for the automatic dark mode and will break the auto dark mode, properties that are not even needed in most cases, or could be improved if devs cared about testing the dark mode with Devtools and just one click.
In the case of Lowes, there is a mix-blend-mode: darken in the images causing the images to get dark like that.
With Brave you can add style rules to modify CSS and that way fix the way the automatic mode works, so that’s all you can do, and it is a nice approach because you can do it per elements not for the whole page as dark mode exclusion list would be (like Opera).
For example, if you want to keep using dark mode in Lowes you can add a lowes.com##img:style(mix-blend-mode: unset !important;) in brave://adblock and done.
If you want to turn it off completely only in lowes website because more incompatibilities, you can do a lowes.com##:root:style(color-scheme: only light !important;) and done, only lowes will not do the auto dark page.
There is a good page that talks about this exact color-scheme property to avoid the automatic dark mode. But it is basically the same thing per page or elements, and just adapt it to the :style() rule in the adblocker.