Color
Bootstrap is supported by an extensive color system that themes our styles and components. This enables more comprehensive customization and extension for any project.
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 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
);
All colors
All 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.
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
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 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,
"skyblue": $skyblue,
"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.
Example
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 v5.1.0Bootstrap 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 v5.1.0.
- To start, make sure you’ve imported our functions, variables, mixins, and utilities.
- Use our
map-merge-multiple()
function to quickly merge multiple Sass maps together in a new map. - 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 "bootstrap/scss/functions";
@import "bootstrap/scss/variables";
@import "bootstrap/scss/maps";
@import "bootstrap/scss/mixins";
@import "bootstrap/scss/utilities";
$all-colors: map-merge-multiple($blues, $indigos, $purples, $pinks, $reds, $oranges, $yellows, $greens, $teals, $cyans);
$utilities: map-merge(
$utilities,
(
"color": map-merge(
map-get($utilities, "color"),
(
values: map-merge(
map-get(map-get($utilities, "color"), "values"),
(
$all-colors
),
),
),
),
)
);
@import "bootstrap/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.