OmniFocus or Calendar with HTML notifications

[tiffle]

@gheharukoh7

I need to have large, colorful, and noticeable notifications

You can get those with alerted. See here:

Custom Apple Persistent Alerts with Actions: Alerter

I grew frustrated by AppleScript's unwillingness to provide access to the macOS functions and styles of Alerts. For clarity, as far as the macOS Notification Center is concerned, Alerts are those notifications that remain on your screen and offer you options, dropdowns, and even text inputs which allow you to take actions. This is as opposed to regular AppleScriptable "notifications," which are Banners, have no functionality, and self-dismiss after a small time. There used to be a unix binary …

Whether you can put it to use with Omnifocus etc is for you to work out! Let us know how you get on!