[d3-chart] fix color for Bar background

[j-mnizhek]

Motivation and Context

HorizontalBar.Background had wrong background color diverging from design. Previous Correct

How has this been tested?

Tested it locally.

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue).
• [ ] New feature (non-breaking change which adds functionality).
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected).
• [ ] Nice improve.

Checklist:

• [ ] My code follows the code style of this project.
• [x] I have updated the documentation accordingly or it's not required.
• [ ] Unit tests are not broken.
• [x] I have added changelog note to corresponding CHANGELOG.md file with planned publish date.
• [ ] I have added new unit tests on added of fixed functionality.