Bootstrap Forced Colors CSS for Windows High Contrast Themes

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Windows has supported High Contrast Themes in Windows since Windows 10. These customizable themes can be useful for users with visual impairments or for users who prefer high contrast colors. When a Contrast theme is activated is enables the forced-colors media query in browsers (at the time of writing, Edge, Chrome and Firefox).

Unfortunately, forced colors mode can cause issues with websites that are not designed to work with high contrast colors. Using Bootstrap v5 has a number of issues with missing borders and elements (This GitHub issue covers some of them) so I’ve created a stylesheet by using the forced-colors: active media query which you can simply add to your site to ‘auto-fix’ everything and adds enhancements to make Bootstrap 5 much more accessible in Firefox, Chrome, Edge on Windows.

Quick start

  • Download the latest release
  • Clone the repository git clone https://github.com/coliff/bootstrap-forced-colors-css.git
  • Install with npm npm install bootstrap-forced-colors-css
  • Install with yarn yarn add bootstrap-forced-colors-css
  • Install with Composer composer require coliff/bootstrap-forced-colors-css

Usage

Add this in the <head> which will load the CSS using a media query as follow: 

<link
  rel="stylesheet"
  href="/css/bootstrap-forced-colors.min.css"
  media="screen and (forced-colors: active)">

The CSS can be loaded via a CDN: 

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/bootstrap-forced-colors-css/css/bootstrap-forced-colors.min.css"
  media="screen and (forced-colors: active)">

Or you can import the CSS into your own CSS file: 

@import bootstrap-forced-colors.min.css

FAQS

What does this fix/improve?

  • Accordion buttons have improved contrast in dark mode
  • Badges within buttons have a 1px border to improve contrast
  • Buttons have improved focus state contrast (2px visible outline rather than 1px)
  • Disabled buttons display the correct color using the GrayText name
  • Carousel indicators have background-color issue resolved
  • Close button has improved contrast by reducing the opacity
  • Dropdown toggle arrows appear correctly (as triangles and not rectangles)
  • List Group disabled items display the correct color using the GrayText name
  • Modal backdrop opacity changed from 0.5 to 0.8
  • Navbar Menu (hamburger) toggle icons display correctly
  • Navs Improves active and focus state contrast
  • Pagination: Active page link has outline to indicate active page
  • Pagination: Disabled page link display the correct color using the GrayText name
  • Placeholder: Fix for invisible placeholder boxes
  • Popovers: Fixes invisible arrow issue
  • Progress: Is no longer invisible
  • Progress: Improved stacked progress bar contrast
  • Spinners: Fixes animation
  • Tables: Have a 1px outline to improve contrast
  • Toasts: Fixes invisible close/dismiss button
  • Tooltips: Fix for arrows appearing as rectangles
  • Tooltips: Add 1px border to tooltips content
  • Vertical Rule: Fixes invisible vertical rule
  • Horizontal Rule: Improves contrast by changing opacity from 0.25 to 0.5

Demo

See this in action at: https://coliff.github.io/bootstrap-forced-colors-css/tests/

Testing

Currently, only Windows 10 & 11 with Edge, Firefox, and Chrome support forced colors mode. To test, you can enable forced colors mode in:

  • Windows 10: Go to Settings > Ease of Access > High contrast and select a theme.
Windows 11: Go to Settings > Accessibility > Contrast themes and select a theme

Windows 11 Contrast Theme Select screen


You can also use the Forced Colors Mode Emulation in Edge and Chrome on all platforms.

Note that CanIUse lists Safari as supporting forced colors mode, however, macOS itself doesn’t have a Forced Colors / High Contrast mode which means it’s not possible to test this with Safari at all.

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Last updated: 2025-12-18
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