What impact Has when a pdf is marked read only

[Former Community Member]

See i have a pdf with 7 page where 6th page show escalate or pass with red and green colour.

But once i right click on pdf and go to property and set pdf read only.

I open the pdf now make any changes and i click on close button it asks whether u want to save the changes before closing.

i choose yes , it asks me to save with different name. i do

now when i open the new form it shows old details and 6th page has some red green fields but most are in black . I dont know y.