Proper UI messaging can improve usability and intuitiveness of a web application.
I usually have 4 categories of messages:
- error (a light shade of red)
- warn (a light shade of yellow/orange)
- notice (a light shade of blue)
- success (a light shade of green)
I only toss “errors” to the user when the app has completely failed and is blocking continuation.
Ideally this would trigger an error.log message or even an email to the site admin. These should be used sparingly, and when form details are not filled out correctly.
I try to use “warnings” on things that will continue, but perhaps give the user an option to go back and improve the request before handling it.