color contrast for yaml with default theme is unreadable

[Sergio Schvezov]

I just opened a snapcraft.yaml from an email attachment on a fresh install of 20.04's daily iso with no theme changes whatsoever and end up with a gedit window where the color contrast is a bit too hard to read (red or blue on dark is not really good).

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gedit 3.34.0-1build1
ProcVersionSignature: Ubuntu 5.4.0-12.15-generic 5.4.8
Uname: Linux 5.4.0-12-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu16
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Feb 6 07:49:22 2020
InstallationDate: Installed on 2020-01-29 (7 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200124)
SourcePackage: gedit
UpgradeStatus: No upgrade log present (probably fresh install)