Burndown Chart: Insufficient color contrast for informative image

Issue Summary

The color contrast of the graph lines is not meeting the minimum color contrast ratio i.e. 3:1.

Steps to Reproduce

1. Navigate to the "Projects" dropdown and activate it.
2. Select the "Scrum" project and activate it.
3. Navigate to the "Side navigation".
4. Navigate to the "Reports" link and activate it.
5. Navigate to the "Switch Report" dropdown.
6. Select the report "Burndown Chart".
7. Observe that "Burndown Chart" page has been appeared on the screen.
8. Use any color contrast testing tool to check the color contrast.
9. Observe that the color contrast between the mentioned image and the adjacent background is insufficient.

Screenshot

Actual Results

In the graph,

• The line which indicates the "guideline" property fails minimum contrast requirement with it's background. FG: #999999, BG: #F2F2F2, Ratio: 2.5:1
• The "guideline" & "remaining values" lines have Insufficient contrast between them. BG: #CF4437, FG: #999999, Ratio: 1.6:1
• The bar section representing non-working days fails minimum contrast requirements with its background. BG: #F2F2F2, FG: #FFFEFF, Ratio: 1.1:1.

This will make it difficult for low vision users to discern meaningful graphics that have insufficient contrast.

Expected Results

For the key parts of all the informative images, ensure that the contrast between foreground, background or adjacent colors is 3:1 to make the image's information accessible for low vision and color-blind users.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available

Environment

MacBook Pro (16-inch, 2019)
macOS Ventura Version 13.3.1
Chrome - Version 112.0.5615.49 (Official Build) (x86_64)
Firefox- Version 112.0.1 (64-bit)
Safari- Version 16.4 (18615.1.26.11.23)
JAWS- Version 2022
NVDA- Version 2020.3
Voiceover - Version Latest