---
title: "system.perspective.setTheme"
description: "Changes the theme in a page to the specified theme."
---

# system.perspective.setTheme

> Changes the theme in a page to the specified theme.

This function is used in **Python Scripting**.

## Description

Note that this function only changes the theme for a single page, not the entire session. To change the theme for a session, write directly to the `session.theme` property instead.

## Syntax

`system.perspective.setTheme(name, [sessionId], [pageId])`

### Parameters
Type | Parameter | Description 
------- | ------- | ------
String | `name` | The theme name to switch to. Possible values are "dark" or "light".
String | `sessionId` | Identifier of the Session to target. If omitted, the current Session will be used automatically. When targeting a different session, then the pageId parameter must be included in the call. [optional]
String | `pageId` | Identifier of the page to target. If omitted, the current page will be used automatically. [optional]

### Returns
Nothing

### Scope
Gateway, Perspective Session

:::note
This function will only work in the Gateway scope if both `sessionId` and `pageId` are supplied to the call.
:::

## Code Examples

```python title="Code Snippet - Changing Session Theme"

# Change the current page's theme to the dark theme.
system.perspective.setTheme("dark")
```