Apple Notes: Text color changes; Dark/Light mode issues

Why does Apple Notes sometimes change the color of the text if I use an "=" sign? I have a few notes similar to this example where I have paragraphs of text, then I will add something with a password, or an email address, etc. The line changes from the default color to the dark green. It does it with email addresses as well, which I kind of understand (even though I'd like to keep it from doing that) but the equal sign seems really odd. Anyone know of a fix?

Using iMac M4 with Tahoe 26.3... but this has been ongoing on some of these notes for years. It's recently gotten to the point of super annoying since I've created many notes with a lot of password information for the recipients of these notes.

Second question... I prefer dark mode. Some of the people that use these notes use light mode. While 95% of the time the text automatically changes for whichever mode a user is using, there are other times that I have to change the color of a paragraph of text as a marker for me to come back to later to edit, as I continue my work further in the note. If I go back and need to edit a small part of the paragraph, and try to change the text color of the whole paragraph back to what I am seeing as white, then it stays white regardless of the mode and does not show for anyone using light mode. Is there a way to change color of the text so it automatically is detected, and the system knows to change it to white (or black) depending on the users mode settings?