Colors

Use a few color utility classes to use color to convey meaning. includes assistance with styling links in hover states.

Colors #

Use a few color utility classes to use color to convey meaning. includes assistance with styling links in hover states.

<p class="text-primary">.text-primary</p>
<p class="text-secondary">.text-secondary</p>
<p class="text-success">.text-success</p>
<p class="text-danger">.text-danger</p>
<p class="text-warning bg-dark">.text-warning</p>
<p class="text-info bg-dark">.text-info</p>
<p class="text-light bg-dark">.text-light</p>
<p class="text-dark">.text-dark</p>
<p class="text-body">.text-body</p>
<p class="text-muted">.text-muted</p>
<p class="text-white bg-dark">.text-white</p>
<p class="text-black-50">.text-black-50</p>
<p class="text-white-50 bg-dark">.text-white-50</p>
  

RESULT

Opacity #

As of version 1.0.0, Sass is used to create text color utilities using CSS variables. Real-time color adjustments without compilation and dynamic alpha transparency modifications are made possible by this.

How it works #

Consider our default .text-primary utility.

.text-primary {
  --bs-text-opacity: 1;
  color: rgba(var(--bs-primary-rgb), var(--bs-text-opacity)) !important;
}

Used a second CSS variable, --bs-text-opacity, for the alpha transparency (with a default value of 1 thanks to a local CSS variable), and utilized an RGB version of the --bs-primary CSS variable (with the value of 13, 110, 253). This implies each time you use .text-primary The value that is calculated is now rgba(13, 110, 253, 1). The internal local CSS variable of each. Because of the way the .text-* class handles inheritance, nested instances of the utility do not necessarily have altered alpha transparency.

Example #

To change that opacity, override --bs-text-opacity via custom styles or inline styles.

<div class="text-primary">This is default primary text</div>
<div class="text-primary" style="--bs-text-opacity: .5;">This is 50% opacity primary text</div>

RESULT

<div class="text-primary">This is default primary text</div>
<div class="text-primary text-opacity-75">This is 75% opacity primary text</div>
<div class="text-primary text-opacity-50">This is 50% opacity primary text</div>
<div class="text-primary text-opacity-25">This is 25% opacity primary text</div>

RESULT

Specificity #

Sometimes the specificity of another selector prevents contextual classes from being applied. Wrapping the content of the element in a <div> or other more semantic element with the correct class can be a suitable fix in some situations.

Sass #

Consider reading about the integrated CSS custom properties (also known as CSS variables) for colors and more in addition to the accompanying Sass features.

Variables #

Most color utilities are generated by our theme colors, reassigned from our generic color palette variables.

$blue:    #0d6efd;
$indigo:  #6610f2;
$purple:  #6f42c1;
$pink:    #d63384;
$red:     #dc3545;
$orange:  #fd7e14;
$yellow:  #ffc107;
$green:   #198754;
$teal:    #20c997;
$cyan:    #0dcaf0;

$primary:         $blue;
$secondary:       $gray-600;
$success:         $green;
$info:            $cyan;
$warning:         $yellow;
$danger:          $red;
$light:           $gray-100;
$dark:            $gray-900;

Grayscale colors are also available, but only a subset are used to generate any utilities.

$white:    #fff;
$gray-100: #f8f9fa;
$gray-200: #e9ecef;
$gray-300: #dee2e6;
$gray-400: #ced4da;
$gray-500: #adb5bd;
$gray-600: #6c757d;
$gray-700: #495057;
$gray-800: #343a40;
$gray-900: #212529;
$black:    #000;

Map #

After that, the theme colors are added to a Sass map so that we can loop through them to create our utilities, component modifications, and other things.

  $theme-colors: (
  "primary":    $primary,
  "secondary":  $secondary,
  "success":    $success,
  "info":       $info,
  "warning":    $warning,
  "danger":     $danger,
  "light":      $light,
  "dark":       $dark
);

Grayscale colors are also available as a Sass map. This map is not used to generate any utilities.

  $grays: (
  "100": $gray-100,
  "200": $gray-200,
  "300": $gray-300,
  "400": $gray-400,
  "500": $gray-500,
  "600": $gray-600,
  "700": $gray-700,
  "800": $gray-800,
  "900": $gray-900
);

RGB colors are generated from a separate Sass map:

  $theme-colors-rgb: map-loop($theme-colors, to-rgb, "$value");

And color opacities build on that with their own map that’s consumed by the utilities API:

  $utilities-text: map-merge(
  $utilities-colors,
  (
    "black": to-rgb($black),
    "white": to-rgb($white),
    "body": to-rgb($body-color)
  )
);
$utilities-text-colors: map-loop($utilities-text, rgba-css-var, "$key", "text");

Utilities API #

Color utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

  "color": (
      property: color,
      class: text,
      local-vars: (
        "text-opacity": 1
      ),
      values: map-merge(
        $utilities-text-colors,
        (
          "muted": $text-muted,
          "black-50": rgba($black, .5), // deprecated
          "white-50": rgba($white, .5), // deprecated
          "reset": inherit,
        )
      )
    ),
    "text-opacity": (
      css-var: true,
      class: text-opacity,
      values: (
        25: .25,
        50: .5,
        75: .75,
        100: 1
      )
    ),