The black theme has been around in Outlook for Windows for some time. However, unlike Outlook Web App, or, Microsoft Teams, the black theme was not a true dark mode. Some aspects of the black theme were still fully illuminated, such as when you read or composed a message.
The screenshot below is an example of how the black theme changes certain aspects such as the folder view and toolbars to black but leaves the email preview pane in white.

Similarly, when you compose an email the message body is also in white.

The new Black Theme for Outlook
Starting with version 1907 for Office Insiders, the Outlook team has extended the black theme so it now incorporates the message body and the composition panes.
Note: Anyone can enroll in the Office Insider program. However, Office Insiders receive weekly updates, which could be subject to bugs.
UPDATE 10-5-19: For those on the Monthly Channel, you can get dark mode with the 1909 monthly channel update (released September 30th).
With version 1907 the message preview pane defaults to black.

Similarly, when you compose an email the message body is now black.

Turning the lights on
It is also possible to turn the lights on for both the message preview and composition screens. This can be useful if an email is not rendering properly in the black theme, or, you simply need to make the message brighter.
To do this in message preview, click the Switch Background button. The icon is represented as the sun.

The message preview will turn to white and the Switch Background button will now be represented as a moon. To turn the lights back off, click the Switch Background button again, which is currently represented as a moon.

The Switch Background button is also available when you are composing an email message. Simply click the Switch Background button to switch the email composition pane between light and dark mode.

Always keep the lights on
If you prefer the old behavior (prior to 1907) where the lights were always on for the reading pane, this option is still available.
Click on the File menu and select Options. From the Outlook Options dialog, select the General tab and check the box Never change the message background color. Click Ok to save your changes. When you select your next email message, and each message thereafter, the lights will remain on.

To revert this change, simply uncheck the previously selected box.
How to switch to the black theme (dark mode) in Outlook
To switch to the black theme in Outlook (and by extension, the entire Office suite), click the File menu and select Office Account.
Under the section Office Theme, pick Black from the drop-down.
You will be immediately switched to the black theme (dark mode).


So, what do you think about the updated black theme? Drop a comment below or join the conversation on Twitter @SuperTekBoy.
Hello
I have the black theme but the email preview pane is still in white. I didn’t find the button for switch background also the moon/sun button. I have looked around in the outlook to find new commands but still missing.
Hi AJ,
You might need to confirm the build and release cycle you are on. I believe for Insiders/Beta and Monthly channel this update dropped in the 1908/1909 time frame.
I wish Microsoft would let user design their own window themes (like it USED to be). They are over 16 million colors and endless combinations, and Microsoft allows four. Talk about Big Brother.
But there is only one color you need for dark mode. 😉
I recommend posting this request to User Voice, Microsoft will read and respond to requests. Top voted items often end up getting developed too – https://outlook.uservoice.com/
As another user posted, this feature requires Office 365 subscription. (It will not show up if you have an Office 2019 license even if you have updated to the appropriate version.)
My question is, since they also added this to OneNote recently, is there any hint of this same feature coming to Excel? I’d love to be able to “flip the switch” and change to a white-on-black theme without actually having to edit colors of the spreadsheet. I hope that they’re working on it.
I have not heard of this feature coming to Excel. Right now, in Excel, all dark mode does is change the ribbon and dialog boxes to dark. But I agree, dark cells would also be awesome.
Looks like someone did request this on User Voice. Be sure to upvote it. Often these requests on User Voice become fragmented, so there may be duplicates out there for this request with higher votes. But this is the one I found – https://excel.uservoice.com/forums/304921-excel-for-windows-desktop-application/suggestions/40848436-dark-mode-excel-cells
I can say that dark mode for the Microsoft Word editor shipped to the beta channel Office users in build 2012 – https://supertekboy.com/2020/11/30/microsoft-word-editor-goes-full-dark-mode/
I’m running 1909 Build 18363.476 but do not have the switch background button or the option to never change the background color. I am enrolled in Insider Monthly. I teach individuals with visual impairments who would greatly benefit from this feature. I appreciate your help.
I’m running 1910 (12130.20272 Click-to-run) on at least three machines. Two of them have the Dark Mode button and setting in options, one machine does not any of that. WTH is going on.
I noticed the Dark Mode button on 1909 version for the first time.
I’m on Outlook for Mac 16.30 (19101301), with an enterprise O365 account, and I still don’t have the dark reading pane and also no “switch background” button in the ribbon. I wonder how this feature is really rolled out…
It seems to be gated behind Office 365 membership which is ridiculous. https://support.office.com/en-us/article/dark-mode-in-outlook-3e2446e0-9a7b-4189-9af9-57fb94d02ae3
This article and the replies are on point! I too want to be able to use this instead of Windows Mail. I too see version 1909 with no dark editing mode. Do I really need to re-install? Is there some way to make the update happen short of doing that?
Hey Alex,
I have corrected my post.
If you are Office Insiders you get dark mode on build 1907.
If you are Monthly Channel you get dark mode in 1909.
When Semi-Annual gets dark mode I will update here.
The 1909 monthly update does not seem to contain the message background changing feature. The messages are still white when using the black theme. The button to change the background is not present. The option to “never change the message background color” is also not present.
Perhaps the feature did not make the update, or perhaps there is something I need to do to turn it on. If so, I do not know what to look for.
About Outlook lists this:
Version 1909 (Build 12026.20264 Click-to-Run)
Monthly Channel
Hey Xavier,
Chris, farther down in the comments, reported a second patch for 1909, that gave them the dark/light buttons in 1909. This may have been the 12026.20320 build (released October 8th), despite the release notes saying 12026.20264. Let me know your findings and I will correct the article. 🙂
I’m in 1909 build 12026.20334 version using 365 ProPlus in monthly channel and
* No “never change the message background color” option
* No Switch Background button
Do you know how these features are distributed ? A re-install is required ?
Thanks
new office update installed, currently in 1909 build 12026.20344 but options are not available yet 🙁
I’m on 1910 x86 on my laptop, which has the “full” dark mode and can switch background in messages.
On my desktop, which is x64 i’m on 1910 and I do NOT have the option to switch the background in messages.
I am actually on Outlook for Mac, not Windows, so I’m not sure if this issue is cross platform or not, but a word of caution about using Outlook Dark Mode that I’ve ran across:
Applied colors by the writer of the email cannot be seen when reading them in the Dark preview panel. So if they’ve highlighted certain phrases, etc, you need to use the “light preview” button manually to see red lettering, for example. Also, if BLACK is applied to original text rather than leaving it the default color, you won’t see it at all in the Dark Preview pane. (And if you’re writer doesn’t indicate anything, important details may be entirely missed because you won’t know to turn the preview pane to Light mode. This happened to me last week.)
On the Mac version we do not have the option to leave the preview pane white by default, so I’ve had reluctantly had to sacrifice the eye comfort of dark mode for the assurance that I’m not missing any key instructions.
Thanks for the tip, Rob. That is good to know. Sounds like I need to invest in a Mac to compare differences.
I’ve got version: 1908(Build 11929.20254) and still dark reading pane is unavailable. When it will be?
I’m on 1908 (Build 11929.20254) and still don’t have the dark reading pane either unfortunately!
Hey all,
I have corrected my post.
If you are Office Insiders you get dark mode on build 1907.
If you are Monthly Channel you get dark mode in 1909.
When Semi-Annual gets dark mode I will update here.
I am on Monthly Channel version 1909. Dark mode is not available, even though I have the black theme selected. Others have noticed this as well and reported in the Office support community. No response from MSFT as of yet.
Thanks for letting me know Chris. All my PCs are on First Release. I am guessing the release notes are either inaccurate or they had to roll it back.
And after posting this, I *just* got another update this morning that added the icon for switching between dark and daylight modes.
What update are you on? I’m on 1909 (Build 12026.20320 Click-to-Run) and I still don’t have it.
So 1907 is finally out, and it’s still not frigging there! Come on you twerps, it’s been YEARS!!!!!!!
Hey Bob,
There are a few different revisions behind 1907. Make sure your build is at least 1907 (build 11815.20002).
Hello there. How can I maintain a bright reading panel in the dark mode for all emails without clicking the button one by one? Thanks.
I’m running 1907 11901.20018 Click-to-Run 64 bit and still have the white reading pane without the Switch Background button. Very strange.
Hey Greg,
I have had a similar issue myself, where it claimed Office was on the latest version (and on the Insider track) but when examining the registry I discovered it was still a part of the monthly channel. The build numbers were purely cosmetic in my instance and it never truly changed between update rings.
For me I did an uninstall, then used SaRA (Supportability and Recovery Assistant) to do a full scrub of Office and reinstalled as an Insider. Then it worked like a charm. I recommend checking out this link – https://insider.office.com/en-us/handbook/for-work-or-school
Still, even that didn’t help 🙁
Sitting on 1910 16.0.12130.20334
Finally with this I can finally move from Windows Mail to Outlook 2019.