Hi there, thanks for your patch. I've added our Yakuake dev as a reviewer.
In the meantime could you format the commit message as described here (https://community.kde.org/Infrastructure/Phabricator#Formatting_your_patch)? Since this is a visual change it would also be good to see a before and after screenshot.
There's a small thing needed here: We need to add Qt::Svg as an explicit dependency, otherwise displaying SVG files only works by accident. But I can do that seperately if you don't want to expand the patch.
Do you have dev access or do you need help landing this?
Does this also fix the blurry button icons in preferences? See https://bugsfiles.kde.org/attachment.cgi?id=120181
The line mentioned by Nate in https://bugs.kde.org/show_bug.cgi?id=407726#c2 is not present.