CoreUI for Bootstrap is supported by an extensive color system that themes our styles and components. This enables more comprehensive customization and extension for any project.


Added in v5.0.0

Bootstrap’s color palette has continued to expand and become more nuanced in v5.0.0. We’ve added new variables for secondary and tertiary text and background colors, plus {color}-bg-subtle, {color}-border-subtle, and {color}-text-emphasis for our theme colors. These new colors are available through Sass and CSS variables (but not our color maps or utility classes) with the express goal of making it easier to customize across multiple colors modes like light and dark. These new variables are globally set on :root and are adapted for our new dark color mode while our original theme colors remain unchanged.

Colors ending in -rgb provide the red, green, blue values for use in rgb() and rgba() color modes. For example, rgba(var(--cui-secondary-bg-rgb), .5).

Heads up! There’s some potential confusion with our new secondary and tertiary colors, and our existing secondary theme color, as well as our light and dark theme colors. Expect this to be ironed out in v6.
Description Swatch Variables
Body — Default foreground (color) and background, including components.
Secondary — Use the color option for lighter text. Use the bg option for dividers and to indicate disabled component states.
Tertiary — Use the color option for even lighter text. Use the bg option to style backgrounds for hover states, accents, and wells.
Emphasis — For higher contrast text. Not applicable for backgrounds.
Border — For component borders, dividers, and rules. Use --cui-border-color-translucent to blend with backgrounds with an rgba() value.
Primary — Main theme color, used for hyperlinks, focus styles, and component and form active states.
Success — Theme color used for positive or successful actions and information.
Danger — Theme color used for errors and dangerous actions.
Warning — Theme color used for non-destructive warning messages.
Info — Theme color used for neutral and informative content.
Light — Additional theme option for less contrasting colors.
Dark — Additional theme option for higher contrasting colors.

Using the new colors

These new colors are accessible via CSS variables and utility classes—like --cui-primary-bg-subtle and .bg-primary-subtle—allowing you to compose your own CSS rules with the variables, or to quickly apply styles via classes. The utilities are built with the color’s associated CSS variables, and since we customize those CSS variables for dark mode, they are also adaptive to color mode by default.

Example element with utilities
<div class="p-3 text-primary-emphasis bg-primary-subtle border border-primary-subtle rounded-3">
  Example element with utilities

Theme colors

We use a subset of all colors to create a smaller color palette for generating color schemes, also available as Sass variables and a Sass map in CoreUI for Bootstrap’s scss/_variables.scss file.


All these colors are available as a Sass map, $theme-colors.

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

Check out our Sass maps and loops docs for how to modify these colors.

All colors

All CoreUI for Bootstrap colors are available as Sass variables and a Sass map in scss/_variables.scss file. To avoid increased file sizes, we don’t create text or background color classes for each of these variables. Instead, we choose a subset of these colors for a theme palette.

Be sure to monitor contrast ratios as you customize colors. As shown below, we’ve added three contrast ratios to each of the main colors—one for the swatch’s current colors, one for against white, and one for against black.

$blue #0d6efd
$indigo #6610f2
$purple #6f42c1
$pink #d63384
$red #dc3545
$orange #fd7e14
$yellow #ffc107
$green #198754
$teal #20c997
$cyan #0dcaf0
$gray-500 #9da5b1
$black #000
$white #fff

Notes on Sass

Sass cannot programmatically generate variables, so we manually created variables for every tint and shade ourselves. We specify the midpoint value (e.g., $blue-500) and use custom color functions to tint (lighten) or shade (darken) our colors via Sass’s mix() color function.

Using mix() is not the same as lighten() and darken()—the former blends the specified color with white or black, while the latter only adjusts the lightness value of each color. The result is a much more complete suite of colors, as shown in this CodePen demo.

Our tint-color() and shade-color() functions use mix() alongside our $theme-color-interval variable, which specifies a stepped percentage value for each mixed color we produce. See the scss/_functions.scss and scss/_variables.scss files for the full source code.

Color Sass maps

CoreUI for Bootstrap’s source Sass files include three maps to help you quickly and easily loop over a list of colors and their hex values.

  • $colors lists all our available base (500) colors
  • $theme-colors lists all semantically named theme colors (shown below)
  • $grays lists all tints and shades of gray

Within scss/_variables.scss, you’ll find CoreUI for Bootstrap’s color variables and Sass map. Here’s an example of the $colors Sass map:

$colors: (
  "blue":       $blue,
  "indigo":     $indigo,
  "purple":     $purple,
  "pink":       $pink,
  "red":        $red,
  "orange":     $orange,
  "yellow":     $yellow,
  "green":      $green,
  "teal":       $teal,
  "cyan":       $cyan,
  "black":      $black,
  "white":      $white,
  "gray":       $gray-600,
  "gray-dark":  $gray-800

Add, remove, or modify values within the map to update how they’re used in many other components. Unfortunately at this time, not every component utilizes this Sass map. Future updates will strive to improve upon this. Until then, plan on making use of the ${color} variables and this Sass map.


Here’s how you can use these in your Sass:

.alpha { color: $purple; }
.beta {
  color: $yellow-300;
  background-color: $indigo-900;

Color and background utility classes are also available for setting color and background-color using the 500 color values.

Generating utilities

Added in v4.1.0

Bootstrap doesn’t include color and background-color utilities for every color variable, but you can generate these yourself with our utility API and our extended Sass maps added in v4.1.0.

  1. To start, make sure you’ve imported our functions, variables, mixins, and utilities.
  2. Use our map-merge-multiple() function to quickly merge multiple Sass maps together in a new map.
  3. Merge this new combined map to extend any utility with a {color}-{level} class name.

Here’s an example that generates text color utilities (e.g., .text-purple-500) using the above steps.

@import "@coreui/coreui/scss/functions";
@import "@coreui/coreui/scss/variables";
@import "@coreui/coreui/scss/maps";
@import "@coreui/coreui/scss/mixins";
@import "@coreui/coreui/scss/utilities";

$all-colors: map-merge-multiple($blues, $indigos, $purples, $pinks, $reds, $oranges, $yellows, $greens, $teals, $cyans);

$utilities: map-merge(
    "color": map-merge(
      map-get($utilities, "color"),
        values: map-merge(
          map-get(map-get($utilities, "color"), "values"),

@import "@coreui/coreui/scss/utilities/api";

This will generate new .text-{color}-{level} utilities for every color and level. You can do the same for any other utility and property as well.