I was editing a .php file when I noticed that the paragraphs that I was editing had a new background colour. I was using the colour scheme “Sixteen” which for normal
paragraphs has grey text on a white background. I had created several new, smaller, paragraphs from an existing one and the new paragraphs had a pale green background, which changed shades as I made edits. I then noticed that the original paragraph had been preserved and had a pale red background. When I tried to delete it I could not, and I couldn’t edit it either.I saved the page an reopened it, and the normal editing behaviour had returned, with no colour shaded backgrounds. I tried to find out what setting I had inadvertently changed which caused the previous behaviour but could not. I am just curious to know more about this feature of ST3.