Theme apply on Microsoft Excel Web Addin.

Question

Theme apply on Microsoft Excel Web Addin.

Dipanjan Tripathi 20

I want to build a features which will fetch 4/5 theme details from a backend and when user will click on a particular colour palate then the theme should be applied on the current workbook. I was trying to apply the theme in current workbook but observed there are no such api exist in office.js to perform this operations. Is there any other way to achieve this functionality or if office.js have any exposed api that can be used in this case?

Accepted answer

0 additional answers

Your answer

Answer 1

Flora-T 3,200 Microsoft External Staff Moderator

Dear Dipanjan Tripathi

Welcome to Microsoft Q&A Forum.

Thanks for reaching out and sharing clear scenario. I totally get what you’re aiming for: let users pick a palette from your service and have the workbook update.

Unfortunately, as you observed, there isn’t currently an Office.js API to read or set the workbook’s Theme or Theme Colors in-place. Office Scripts and the Excel REST APIs also do not provide a way to change the workbook theme.

However, you may consider a few workarounds:

Coordinate your add-in UI with the Office app theme

Office.js only exposes the Office app’s UI theme via Office.context.officeTheme and Office.onOfficeThemeChanged so your task pane matches Light/Dark and accent colors.

Simulate a “theme” in the workbook by applying consistent formatting yourself

Update built-in cell styles (Normal, Heading 1–6, Title) so users see your palette as they work.
Standardize table styles and recolor header/body ranges.
Recolor chart series and titles/axes to your palette.
Format shapes (fills/lines) and, if relevant, PivotTables and slicers.

Note: This provides a consistent look, but it does not change the underlying Theme/Colors in Page Layout. Existing and future content won’t auto-recolor in the same way a true theme change would.

While this Q&A forum is a valuable space for sharing insights and receiving technical guidance, the most effective way to influence product development is by submitting feedback directly to Microsoft. You can do this via Help > Feedback in the Excel app or through the Excel Feedback Portal.

At Microsoft, accessibility and user experience are top priorities, and feedback like yours plays a crucial role in shaping future improvements.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Dipanjan Tripathi 20 Reputation points

2025-08-22T08:14:15.46+00:00

Hi Flora, is there any way to manipulate the underlying theme of the current workbook because i want to apply one colour palate when user will select it
Flora-T 3,200 Reputation points Microsoft External Staff Moderator

2025-08-22T14:52:41.8366667+00:00

Good day Dipanjan Tripathi

Thanks for the follow-up. You're trying to get to the core of the file, and I understand you're looking for a way to directly change the actual workbook theme, not just simulate it.

Unfortunately, there is no way for an Office.js add-in to manipulate the underlying theme of the current, open workbook.

The Office.js sandbox is designed for security and performance, and it doesn't expose direct access to the underlying file format (OOXML) for in-place modification. Changing the workbook theme would require rewriting a fundamental part of the workbook file, and that capability is not available through the JavaScript APIs today.

I understand this isn’t the response you were hoping for since a direct API would be far more effective. The fact that this request is being raised again highlights how essential this functionality is. Your persistence reflects a real need that deserves attention.

Sharing insights like this helps Microsoft better understand practical use cases and prioritize meaningful improvements. I encourage you to submit feedback ideally including a voice-specific scenario.

As a forum moderator, I’ll do my best to help guide discussions and share insights based on Microsoft documentation and community experience.
Flora-T 3,200 Reputation points Microsoft External Staff Moderator

2025-08-25T14:23:30.56+00:00

Hi Dipanjan Tripathi

I just wanted to follow up on this thread. It has been a while, and I was wondering if you've had a chance to check the replies provided.

I genuinely appreciate you taking the time to share this scenario, it truly means a lot. I understand how important this functionality is for creating a seamless branding experience for your users, and I want you to know that your voice is heard. Ensuring a smooth, powerful, and developer-friendly experience is something we care deeply about, and insights like yours play a key role in helping us improve the platform.

While I don’t have access to internal engineering roadmaps or influence over product development decisions, I’m here to support you as best I can. Whether that’s clarifying the workarounds, sharing documentation, or making sure your concerns are directed to the right feedback channels.

Please keep the feedback coming, it really does help drive change.

Share via

Theme apply on Microsoft Excel Web Addin.

0 additional answers

Your answer