back and forward button background looks out of place with accessibility themes

[Robert Roth]

Steps to reproduce:
1) From System Settings-.User Interface-> Appearance set either HighContrast or HighContrastInverse as the theme
2) Observe the back and forward buttons background
Expected:
The background should be the same color as the toolbar's color
What happens:
The background color of the buttons is inverted: either light (if the toolbar background is dark) or dark (if the toolbar background is light).
See the screenshot attached:

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: software-center 5.1.7
ProcVersionSignature: Ubuntu 3.2.0-11.19-generic-pae 3.2.1
Uname: Linux 3.2.0-11-generic-pae i686
ApportVersion: 1.91-0ubuntu1
Architecture: i386
Date: Sun Jan 29 11:27:27 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20120110.2)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: software-center
UpgradeStatus: Upgraded to precise on 2012-01-28 (1 days ago)

[Robert Roth (evfool)]

Still a problem with software-center 5.2.1 on Precise.