---
Title: Theming an ADF app
Added: v2.0.0
---

# Theming an ADF app

**Theming** is the process of adding your own color scheme to add style to an existing design.

The [Material Design](https://material.io/guidelines/material-design/introduction.html)
specification doesn't specify a single color scheme. Instead it uses the concept
of color **themes** to allow designers some flexibility in their choice of colors.

A theme is a palette based around two main colors: the **primary** color (used widely
throughout the app) and the **accent** color (used mainly for highlighting and calling
out specific UI elements). Each of these colors is defined in a number of shades. For
example, a blue/orange theme could define shades like the following:

![Theme swatches](../docassets/images/ThemeSwatches.png)

Each shade is related to a particular purpose or set of purposes within the app. So for
example, the shade that works best for text isn't necessarily the same shade you would use
for flat areas of color. Material Design provides a number of
[standard themes](https://material.io/guidelines/style/color.html#color-themes)
with shades that are carefully chosen for each purpose within the UI. The CSS files are
designed so that the names are consistent between themes (so the same "purpose" will always
have the same class name across CSS files). This makes it easy to switch themes simply by
changing a few CSS definitions. Material Design also defines the relationship between
the different shades, so you can calculate your own color values or, more straightforwardly, use
an [online palette design tool](http://mcg.mbitson.com/).

See the [Material Design Style page](https://material.io/guidelines/style/color.html#) for
more information about color concepts.

## Defining a custom theme

When you want more customization than a pre-built theme offers, you can create your own theme file. You only need to include the packages you actually use in your application.

```scss
/*
 *  Include only packages that you are using (and core by default)
 */
@use '@angular/material' as mat;
@import '~@angular/material/theming';
@import '~@alfresco/adf-core/theming';

@include mat.core();

$primary: mat.define-palette($alfresco-accent-orange);
$accent:  mat.define-palette($alfresco-accent-purple);
$warn:    mat.define-palette($alfresco-warn);
$theme:   mat.define-light-theme((
    color: (
        primary: $primary,
        accent: $accent,
        warn: $warn,
    ),
    typography: $alfresco-typography
));

@include angular-material-theme($theme);
@include alfresco-material-theme($theme);
```

### Multiple themes

You can create multiple themes for your application:

#### Example of defining multiple themes

```scss
@import '~@angular/material/theming';
@import '~@alfresco/adf-core/theming';

@include mat-core($alfresco-typography);

$primary: mat.define-palette($alfresco-accent-orange);
$accent:  mat.define-palette($alfresco-accent-purple);
$warn:    mat.define-palette($alfresco-warn);
$theme:   mat.define-light-theme((
    color: (
        primary: $primary,
        accent: $accent,
        warn: $warn,
    ),
    typography: $alfresco-typography
));

$dark-theme:   mat.define-dark-theme((
    color: (
        primary: $primary,
        accent: $accent,
        warn: $warn,
    ),
    typography: $alfresco-typography
));

@include alfresco-material-theme($theme);
...like above

.adf-dark-theme {
    @include alfresco-material-theme($dark-theme);
    ...like above
}
```
Any component with the `add-dark-theme` class will use the dark theme, while other components will fall back to the default.


## Default reusable class

```css
.accent-color                // Accent color
.warn-color                  // Warn color
.primary-contrast-text-color // Default contrast color for primary color
.accent-contrast-text-color  // Default contrast color for accent color
.background-color            // Dialog background color
.primary-background-color    // Primary background color
.accent-background-color     // Default background color for accent
```

## Styles

Avoid adding css variables with names related to components:
```
--my-component-nr-xxx-background-color: mat.get-color-from-palette($primary, 50),  // bad
--theme-primary-color-50: mat.get-color-from-palette($primary, 50)  // good
```

Avoid adding css variables with custom values, values should come from the theme:
```
--new-variable: yellow  // bad
--new-variable: mat.get-color-from-palette($primary, 50), // good 
```

When styling components try to use theme related variables (colors, typography):
```
.my-class {
  color:darkgrey;  // bad
  color:var(--theme-primary-color);  // good
  font-size:23px; // bad
  font-size:var(--theme-typography-body-1-font-size); // good
  background:yellow; // bad
  background:var(--my-component-nr-200-background-color);  // bad
  background:var(--theme-primary-color-50);  // good
}
```

When using library like Angular Material try to follow patterns from this library. 
It helps to style components built with this library (just apply theme instead of custom styling). 
For example when creating input:
```
// bad
<div class="my-custom-input">
  <div class="my-custom-label"></div>
  <mat-form-field>
    <input type="text">
  </mat-form-field>
  <div class="my-custom-error"></div>
</div>

// good
<mat-form-field>
  <mat-label></mat-label>
  <input type="text">
  <mat-hint></mat-hint>
  <mat-error></mat-error>
</mat-form-field>
```