Poor contrast in some applications

[Lee Clark]

In some applications the contrast between the background and text colour is very poor when using the Yaru theme in "Dark Mode".

For example, If the theme is set to Dark via the settings application under "Appearance" and gedit (GNOME Text Editor" is launched. The background of the line the cursor is on is light very similar to the text colour.

I've attached a screenshot.

In the "Standard" mode the theme subtly highlights the current line. But this is not the case for the "Dark" mode.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: yaru-theme-gtk 20.04.4
ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27
Uname: Linux 5.4.0-21-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu22
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 2 17:46:15 2020
InstallationDate: Installed on 2020-03-20 (12 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200320)
PackageArchitecture: all
SourcePackage: yaru-theme
UpgradeStatus: No upgrade log present (probably fresh install)