When the text is set to non-accentable, it always appears white. The background is accentable, but when the user changes the tint color to white, the text becomes invisible.
How can I make it work like in the Shortcuts widget, where the text color automatically changes based on the tint of the background, ensuring the text is always visible?
Like many things in Apple’s widgets, they are doing things we don’t have access to. If there is a way to do what you are looking for, I would love to know what it is, but based on my testing there is literally no way to make text be any color other that white or the accent color with some level of opacity.
On top of that, the Widget views have no way of knowing what the accent color is so there is no way to adjust based on having a light or dark accent color.
Our inability to really layer things and maintain readibility is one of the many shortcomings in the tinted widget system that came out this year
There's no supported way for you to use tints similar to the system apps with the APIs currently available. If you'd like us to consider adding the necessary functionality, please file an enhancement request using Feedback Assistant. Once you file the request, please post the FB number here. If you're not familiar with how to file enhancement requests, take a look at Bug Reporting: How and Why?
This answer may be helpful: https://forums.developer.apple.com/forums/thread/763246