Yes, if you are changing the colors now in the style properties, they won't change in the frontend. You need to adjust the color code in the extra.less template now.
Simple browser inspector tool.
Add this to your extra.less:
[data-notice-id="-1"].notice--cookie .js-noticeDismiss.button--notice.button, .notice--cookieAdvanced .cookies-buttons .button--primary {
color: #fcfcfc !important;
background: #e8264d !important;
}
See if it changes anything.
Settings in style properties should work for these buttons too. It works fine on my side. Maybe it is overwriting something (from extra.less?).
You can do it manually with this in your extra.less template:
@media (min-width: @xf-responsiveMedium) {
.u-bottomFixer [data-notice-id="-1"] {...
You can't control that from the public navigation.
I have an add-on where you can control that: https://xenforo.com/community/resources/cxf-whats-new-tabs-on-forum-list.8362/
It does not support all the 3rd-party add-ons that add their stuff here. But you can manually edit templates for those.
I can agree with Mr Lucky here. I tried it on two forums with different niche, but there was no benefit from it. The bot is retired for quite some time now and I'm not thinking to wake him up again.