I dont think so.
The default icon from the the icon theme for start-here-kde
will continue to be the default for the application menu.
You can look for an alternative.
For example, there should be the path /usr/share/icons/manjaro
present on your system.
I can also share mine if you want some;
Teal ‘Maia’
https://0x0.st/Xsje.svg
White
https://0x0.st/Xsju.svg
(if your background is white you may not see it, but its there. You can also download like, ex
curl -O https://0x0.st/Xsju.svg
)