You can view the current war index, including painting, by selecting the link on left side of the war console. This is important in general to see your progress towards victory. It is important to note that the war must end with an attack even if painting adds damage points sufficient for victory. If you have added sufficient points through painting, you can even launch an attack against an undefended target, where no shots are exchanged, and end the war.
Following a good guide can avoid these errors. Like this one:
https://www.simcountry.com/discus/messages/16295/25063.html?1440694028 On that note, check item #8 of the guide that states:
"8. Move the special forces units you dropped around the country. This will "paint" the country, occupying territory that will allow you to win. Check the War Index of the c3 and look to see you get all 25 occupation points. Also, after getting the occupation points, check the total War Index of the c3. If it is zero, or less, you can attack the defenses of a county/town with either Unit 1 or 2 , for no losses, and win the war at that point, and skip step 9."