[a11y][Violation][1.4.3 Contrast (Minimum)] Text contrast issues reported on Notebook UI

[nkn2022]

Description

I am running an accessibility test suite with Notebook UI using the IBM Equal Access Accessibility Checker tool on Chrome browser. The results look good overall, only a few things are missing to reach a first formal level of compliance. So kindly help look into these.

Issues reported were violating WCAG 2.2 requirements.
Ref: https://www.ibm.com/able/requirements/checker-rule-sets

Full report (includes information on element locations where issue were found):
Accessibility_Report-7a73e10e-f8a4-4a06-a78d-5174a1309c5b.xlsx

Category: 1.4.3 Contrast (Minimum)

Ref: https://www.ibm.com/able/requirements/requirements/?version=v7_3#1_4_3)

Violation of Rule: text_contrast_sufficient

List of issues with elements that violate this rule with a screenshots

Issue 1
Text contrast of 4.17 with its background is less than the WCAG AA minimum requirements for text of size 13px and weight of 400
Element location:
<span class="ͼ11">
Screenshot:

Issue 2
Text contrast of 4.26 with its background is less than the WCAG AA minimum requirements for text of size 13px and weight of 400
Element location:
<span class="ͼu">
Screenshot:

Reproduce

• Install Chrome extension for IBM accessibility checker tool. Ref: https://www.ibm.com/able/toolkit/verify/automated
• Open Notebook UI on Chrome browser. Add some cells with code.
• Run the tool and we can see the above Violations reported.

Here is the screenshot of the UI scanned for the attached report:

Expected behavior

The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, with a 3:1 ratio for large-scale text.
Reference on how to fix this issue can be found in these links:
https://www.ibm.com/able/toolkit/design/visual/#text-color-contrast

[RRosio]

Linking jupyterlab/jupyterlab#16888

[nkn2022]

@RRosio The JupyterLab issue has been closed as a false positive for the tool. But please note that the issues mentioned here reference different areas of the UI. So these will need further investigation.