yara std theme background is transparent in GnuCash dropdown list for entry behind mouse pointer

[Chris Good]

1) Ubuntu version: Ubuntu 20.04.2 LTS

2) Package version: yaru-theme-gtk version 20.04.10.1

When using the latest GnuCash Flathub 4.5 (but I believe all GnuCash versions 3.0 and later have the same problem) and the Yaru Standard application theme, when moving the mouse pointer thru a dropdown list, the background of the line behind the current mouse pointer is transparent, so you can see the foreground text of the item in the list, and in the background, whatever is under the dropdown list. This makes it very hard to read.

See https://lists.gnucash.org/pipermail/gnucash-user/attachments/20210513/ae179ec6/attachment.png
for an example display of this problem.

The Yaru Light and Dark themes and also Adwaita (default), do NOT have this problem.

3) Expected result: the background color of the dropdown list should be white, like other lines.

Refer https://bugs.gnucash.org/show_bug.cgi?id=797493

[Chris Good (chris-good)]

Problem still exists in Ubuntu yaru-theme-gtk 20.04.11.1 available in focal-updates.
See also https://github.com/ubuntu/yaru/issues/2841 raised automatically by github-actions bot from this launchpad bug.

[Frederik Feichtmeier (frederik-feichtmeier)]

This specific theme has been replaced with yaru-light
Eventually we could Backport the current yaru theme (minor gnome shell) to 20.04?