Suggestions:
- Make the text of the error message larger. Much larger.
- For dark themes, use a white background in the error message, and vice versa.
- Alternatively, put a high-contrast border around the error message.
In addition, add the current error to the message in the bottom status bar so it reads something like this:
PHP error on line 61: Syntax error, unexpected '$dbw' (T_VARIABLE) on line 61
Full disclosure: My eyes are 70 years old. They can't compete with you young kids out there, but this idea is a good one for everybody.