Hello, Cal Ratcliff
Welcome to Microsoft Community.
Thanks for your feedback, I understand that you are having trouble on using your Outlook new.
I understand that you want to use the mail time reminder and calendar color change feature on Outlook new, after my testing, currently Outlook new does not have time reminder, the new Outlook is more like Outlook Web than classic Outlook so there may be some features different, I understand that you are a Microsoft 365 subscriber, if you want to use these two features, then it is recommended that you fall back to classic Outlook use.
Calendar color can change refer by this link:
Webmail - how to change default appointment colour - Microsoft Community
If you want to go back to the Outlook version, you can turn on Outlook new, find the button in the upper right corner and click on the back, if you don't have this button, you can also find help - go to Classic Outlook to go back to Classic Outlook to use.
For more information, please refer to the following link:
Toggling out of the new Outlook for Windows preview - Microsoft Support
We welcome your feedback on our products through the links below
Contact support and provide feedback in new Outlook for Windows - Microsoft Support
I wish you all the best and hoping you'll get a resolution there.
Hardyjoe.J|Microsoft Community Support Specialist