Environment:

Mail Sender: MAC with Outlook:mac 2011 Version 14.6.1 (160122)

Mail Receiver: Surface Book, Windows 10 with Outlook 2016 Version 16.0.6568.2025

Mail Receiver: Surface Book, Windows 10 MAIL Client 

Issue:

Our marketing department uses MAC's, I know right, but like goes on. I would receive emails from our marketing department and some outlook signatures looked great and other had the wrong color.

If a MAC user dragged the PNG from the MAC desktop to signature template it would strip the color profile from the image. To the human eye all looks great but when mail was received by Surface Book with Outlook 2016 Version 16.0.6568.2025 it looked terrible. If I opened that same email in the Windows 10 mail client it looked perfect.

Further troubleshooting:

If the MAC user opened the image from Chrome and copied it and pasted it into the Outlook:mac signature template it included the color profile. Problem resolved.

In order to deliver a great Outlook:mac experience it would be nice if the Office team could resolve this to prevent this issue with other users.