While looking over the vSphere 8 release notes, I had noticed there was also release notes for new version of the ESXi Embedded Host Client, which is an HTML 5 UI for accessing standalone ESXi host. The really interesting feature that stood out to me was the following:
Ability to change the user interface theme
Initially, I thought this was referring to the new "gray" theme which is the default when logging in.
I thought it was a bit strange to refer to this as being able to change user interface. What I did not realize was that the theme editor for the ESXi Host Client was actually hiding else where in the UI ... Thanks to Mark Gabbs for sharing the details!
UPDATE (10/12/22) - After publishing this blog post, I noticed a more detailed article was posted on the VMware Blog regarding the new ESXi Host Client 2, which includes even more new features such as markdown support for customizing the ESXi DCUI and Host Client login window.
If you navigate to the upper right and click on Help->About, you will now see a new UI Preference Theme selector:
You will now see three options including Light, Dark and Classic. It turns out the theme you see by default with ESXi 8.0 is actually using the "Light" theme, which I know there has been mixed feelings on. If you toggle to the "Dark" theme, you will now get a proper dark mode and I certainly prefer this option by default!
Hopefully this is something that is being considered for the vCenter vSphere UI Client as I know customization of themes and colors has been frequently requested by customers since 2015!