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## 4.2 Themes

Use Themes, including Universal Theme, to define the layout and style of applications.

Important:

Oracle recommends using Universal Theme for creating accessible apps.

This guide is written for use with the Universal Theme. This guide does not support customized themes directly. While some discussion applies generally to all apps, many discussions are specific to Universal Theme.

- About Accessibility Features in Universal Theme
  Universal Theme is an accessibility-optimized theme for Oracle APEX.
- About Accessible Theme Styles
  Mark a theme style as accessibility tested if it meets appropriate accessibility standards.
- About Theme Roller
  Use Theme Roller to customize Universal Theme.

Parent topic: Developing Accessible Apps

### 4.2.1 About Accessibility Features in Universal Theme

Universal Theme is an accessibility-optimized theme for Oracle APEX.

Universal Theme (also called Theme 42, or abbreviated as UT) was first introduced in Oracle Application Express 5.0 to improve out of the box usability and accessibility for Oracle APEX apps.

While you can create and use your own fully accessible custom themes in APEX, this guide only provides instructions for apps using Universal Theme.

Oracle strongly recommends migrating from older themes to Universal Theme. See the Universal Theme migration guide for further assistance.

Parent topic: Themes

### 4.2.2 About Accessible Theme Styles

Mark a theme style as accessibility tested if it meets appropriate accessibility standards.

Theme styles enable you to change the look and feel of an app without switching to an entirely different theme.

Oracle recommends using the default Oracle APEX theme style Vita for best accessibility.

You can mark theme styles in APEX as accessibility tested. Because the underlying CSS of a theme style affects the overall accessibility of an app, you can mark a theme style as accessibility tested if you are confident that it meets the appropriate accessibility standards that you or your organization must adhere to. The Vita theme style is accessibility tested.

Parent topic: Themes

### 4.2.3 About Theme Roller

Use Theme Roller to customize Universal Theme.

Theme Roller is a developer tool in the application runtime for analyzing and declaratively adjusting the style settings of Universal Theme without needing to know the underlying CSS.

Some color combinations cause accessibility issues due to a lack of contrast. To help prevent this, Theme Roller has automatic color contrast checking that analyzes your app’s compliance with WCAG 2.0 contrast standards. Theme Roller notifies you if a setting passes or fails this contrast check.

Description of the illustration theme_roller_color_contrast_check.png

A check mark appears next to color combinations for settings to indicate that the color contrast defined meets the minimum required ratio. The ratio is also included next to the check mark.

To learn more about minimum color contrast, see WCAG 2.1 Understanding Success Criterion 1.4.3: Contrast (Minimum).

Parent topic: Themes