How to customize the office 365 theme – As an administrator of a office 365 business subscription, you can change the default theme displayed in the top navigation bar for everyone in your organization:
- Add your company logo.
- Change the colors to match the rest of your brand.
- Add a destination link users go when they select your logo.
Customize the Office 365 theme in the admin center
Step 1: In the admin center, go to the Settings > Org Settings page, and then choose the Organization profile tab.
Step 2: On the Organization profile tab, choose Custom themes.
Step 3: On the Customs themes panel, change the theme elements that you want for your organization:
- Use custom logo image: Choose whether to use the image in the URL or upload the image. If you use a URL, make sure that the URL uses HTTPS, and the image is 200 x 30 pixels, any size and any format. You can upload a logo under 10 KB in JPG, PNG, GIF or SVG format. The logo is 200 x 30 pixels.
Note: In order for the logo to be displayed in the SharePoint mobile application, please use only SVG images. Images uploaded in any other format will not be displayed in the app. The logo is not clickable in the SharePoint Mobile application.
- Make the logo clickable: You can use the logo in the navigation bar as a link to any company resource. You can enter the URL of the logo here, starting with http:// or https://. This is optional.
- Choose a background picture: choose a picture, then upload your own JPG, PNG or GIF with a resolution of 1366 x 50 pixels and no more than 15 KB. The background image appears in the top navigation bar of each page.
Note: Images containing text may not display as expected. The built-in elements that appear on the right and left sides of the navigation bar may vary from service to service, and these elements may obscure your text.
- Navigation bar color: select the color used for the background of the navigation bar. The navigation bar appears at the top of each page.
- Text and icons: Choose a color for text and icons on the top navigation bar.
- Emphasis color: Choose a color for the hover color of navigation bar buttons and the page emphasis on some applications (such as buttons and text).
- Prevent users from overwriting themes: Flip this switch to prevent users from choosing their own theme from our theme selection. This will not prevent users from setting high contrast themes.
- Display user name: Choose whether to display the user’s full name at the entrance of the account manager in the upper right corner of the page when the user logs in. By default, users will see that their photo or initials of their name (if there is no photo) have been uploaded.
Step 4: Choose Save changes.
Hope to help you !
More: Use the mail recall function to retrieve the mail you sent from the recipient’s mailbox that has not been opened. Read more article to Resend or Recall an Email in Office 365.