--- layout: docs title: Customization options group: getting-started --- With Bootstrap 4, we've added a handful of global options for easily customizing all the components in your project. These options are handled by Sass variables. Simply change a variable's value and recompile with the included Gruntfile. ## Available variables You can find and customize these variables in our `_variables.scss` file. | Variable | Values | Description | | --------------------------- | ---------------------------------- | ----------------------------------------------------------------------- | | `$spacer` | `1rem` (default), or any value > 0 | Specifies the default spacer value for our spacer utilities. | | `$enable-flex` | `true` or `false` (default) | Swaps `float` and `display: table` styles for `display: flex`. | | `$enable-rounded` | `true` (default) or `false` | Enables predefined `border-radius` styles on various components. | | `$enable-shadows` | `true` or `false` (default) | Enables predefined `box-shadow` styles on various components. | | `$enable-gradients` | `true` or `false` (default) | Enables predefined gradients via `background-image` various components. | | `$enable-transitions` | `true` (default) or `false` | Enables predefined `transition`s on various components. | | `$enable-hover-media-query` | `true` or `false` (default) | ... | ## Color palette Bootstrap's color palette includes a numerical range of shades for each base color, heavily inspired by [Google's color palette](https://www.google.com/design/spec/style/color.html#color-color-palette). Base colors, which utilize Sass color functions to generate each shade, are indicated at the top of each stacked palette.
100
100
200
300
400
500
600
700
800
900
500
100
200
300
400
500
600
700
800
900
500
100
200
300
400
500
600
700
800
900
500
100
200
300
400
500
600
700
800
900
500
100
200
300
400
500
600
700
800
900
500
100
200
300
400
500
600
700
800
900