Appsemble 0.13.4
Getting Started
Basic appDNSNotificationsOauth2ResourcesSecurityStudioThemingTheme optionsCustom Styling


By default Appsemble provides a default style based on the Bulma CSS framework. While this is completely functional for end users, developers may be interested in further spicing up their applications by applying their own style and branding.

To support this, Appsemble supports customizing the styling in two different ways: Theme options for setting basic colors and custom styling for advanced or more specific styling.

Theme options

The Bulma CSS framework uses a set of colors for different parts of its elements. Appsemble supports customizing a subset of these variables by including a theme object at different points within an app recipe.

The supported variables are:

  • themeColor
  • splashColor
  • primaryColor
  • linkColor
  • successColor
  • infoColor
  • warningColor
  • dangerColor
  • tileLayer

The themeColor and splashColor variables are not visible at all times. These define the colors that appear when starting up the app after installing it on a mobile device.

Each variable can be assigned with a hexadecimal value representing the desired color.

They can be accessed in the CSS using custom variables using kebab-case, for example: background-color: var(--primary-color). An appropriately readable shade for the text of each color can be found by appending -invert to the variable name.

Aside from color-related theme properties, the tile layer used on components that display a map (such as map and form) can be customized using the tileLayer property by specifying a URL template.


primaryColor: '#229954' # Green
linkColor: '#D68910' # Orange
successColor: '#76448A' # Purple
- name: Red Page
primaryColor: '#FF0000' # Red
- type: example
version: 0.0.0
primaryColor: '#0000FF' # Blue
- type: example
- name: Some Other Page

The above example sets the app´s primary color to green, the color of its links to orange and the color of ´success´ elements to purple. The page Red Page overwrites the primary color to be red and one of its blocks overwrites the primary color to be blue instead.

If a theme variable is not overwritten, it will simply use the theme of its parent.

Note: The above example does not represent a full app. It is merely a representation of how app themes can be defined.

Bulma Extensions

On top of the base Bulma framework, extensions have been added that also benefit from all the variables Bulma uses. The list of extensions is as follows:

Appsemble classes

In addition to Bulma classes, Appsemble has defined the following classes in the core part of Appsemble. These may also be used for styling.

CSS ClassContextDescription
.bottom-navBottom app navigationThe container element.
.bottom-nav-itemBottom app navigationA navigation list item.
.bottom-nav-item-linkBottom app navigationA link inside a list item.

Custom Styling

Custom styling is supported using a hierarchical model by allowing developers to upload CSS which gets injected during the runtime of an application. Stylesheets can be uploaded at three different levels and can be injected at three different points within applications.


App Block
App Core
App Shared
Organization Block
Organization Core
Organization Shared
Server Block
Server Core
Server Shared
Default Style (Bulma CSS)

Applications can be styled at a server level, organization level as well as the app-specific level. Within each level, styling can be further specified for core modules, block modules and shared modules.


Server-level styling gets applied to every application hosted on the Appsemble server. This is useful for quickly applying style changes without having to re-deploy the server.

Organization-level styling gets applied to every application that belongs to a specific organization. This is useful for applying unified styling across every application within an organization, such as for supplying basic color themes and icons.

App-level styling gets applied to one specific application. This is primarily used for any styling that is directly related to one specific application without influencing any other applications. App-level styling overrides any styling applied at organization and server levels.


Core-module styling gets applied to any part of an Appsemble application not related to a block, such as the navigation bar, side menu, login view, message toasts, etc. The styling applied to the core modules do not get applied to blocks.

Block-module styling gets applied to a specific block.

Shared-module styling gets applied to each individual block as well as the Appsemble core modules. This is useful for applying styles to elements that can appear in both the core modules as well as blocks, such as input fields. It can also be used to apply CSS variables

Applying themes for an application

Open the Appsemble studio located at the base URL of Appsemble. Login, and create your first app. Within the editor, tabs for shared and core are available. These tabs contain the current styling for these modules. Tabs containing styling for specific blocks are automatically added and removed depending on which blocks are used within the app recipe.

To preview a style change, simply enter CSS in the corresponding tabs and press the Save button. If the styling is satisfactory, it can be uploaded to the application by pressing the Upload button.

Example shared styling:

.button {
border-radius: 0;
box-shadow: 5px 5px #888888;
font-family: serif;

Example core styling:

.navbar {
background-color: var(--primary-color) !important;
.navbar-item {
color: var(--primary-color-invert) !important;
padding: 0 !important;

Example block styling for @appsemble/form:

form {
max-width: initial !important;
padding: 0 !important;
} {
box-sizing: border-box;
max-width: 100vw;
padding: 0.5em 1em;

Applying themes for an organization

Organization themes can be uploaded using the CLI. The command for uploading themes is as follows:

yarn appsemble theme upload [path-to-theme-css] --organization [organization-id] [--shared|--core|--block @organization/blockname]

More detailed information about the meaning of each parameter can be found using the following command:

yarn appsemble theme upload --help

Applying themes for server

Not yet implemented.