After applying System High Contrast theme, Keyboard focus indicator not visible (very low luminosity ratio).:A11y_WPF_HighContrast

GitHub Tags:

#A11ySev2; #A11yTCS; #WCAG1.4.11; #Win32; #DesktopApp; #Win11; #WPF; #BM_WPFRuntime_Win32_JUNE2025; #ContrastTheme; #a11ydb-focus-low-contrast;

Issue Subcategory:

Focus indicator has low contrast

User Experience:

People who are primarily using keyboard to navigate and have low vision may not be able to see where focus is located, making keyboard navigation hard to follow.

Repro Steps:

Launch the sample app> Apply aquatic contrast theme> Observe the issue.

Actual Result:

After applying the System High Contrast theme, the keyboard focus indicator becomes difficult to perceive because it has a very low luminosity contrast ratio of 1.206:1 against the surrounding background. Users navigating with the keyboard may be unable to determine which element currently has focus.

Expected Result:

The keyboard focus indicator should remain clearly visible in System High Contrast mode and meet the applicable contrast requirements for focus appearance.

How to Fix:

Adjust the focus indicator color to achieve 3:1 contrast. Consider using a thick (2px+) outline with a contrasting color, or combine outline with box-shadow for visibility on varied backgrounds

Environment details:

Application Name: WPF

Note:

"Please do not close this bug. This bug should only be closed by TCS, C+AI Accessibility tester after bug verification."
"Contact CAI Accessibility Support Channel for Accessibility queries on design, development, test, usability or any processes"

Attachment:

Start by locating the sample app described in the repro steps and reproduce the issue with the aquatic System High Contrast theme. Inspect the WPF focus-indicator styling and its surrounding background; done means the indicator is clearly visible and reaches the stated 3:1 contrast target in that scenario.