Gelbooru Visited and Type Highlighter
Adds colored borders to all pages on Gelbooru.com that show image listings (search pages, pools, etc) to show any images you have already viewed. Also shows which images are animated.
Default colors: very light blue for unvisited, green for visited, yellow for unvisited animated gif or png, purple for visited animated gif or animated png, a less painful to look at shade of blue from the default for unvisited WebM, and red for visited WebM. You can customize these by using the settings link on the right side of the header. Animated png/gif highlighting will only work if the image has been tagged correctly, since unlike with webm there is no real way to tell them apart otherwise.
Links to image pages in your browser history are also highlighted via CSS, but browsers automatically clear pages from history after a while, so that will only work in the short term. There is no way to detect visited links from browser history in JavaScript for privacy reasons, so there is no way to automatically import those into this script's long-term storage. Therefore anything highlighted as visited due to your prior browsing history will go away after a while unless you click on them again while this script is running. Anything in your browser history that has not been added to this script's data yet will have an extra gray frame inside the main border as a reminder.
Important Note: Clearing your browser data will clear the visited history, because this script stores all data locally within your browser. It never stores any data elsewhere itself. You can make backups of your data or transfer it between browsers and devices by using the "Visited History Backups" item on the right side of the header.
This will not work on other Boorus, because the implementation is specifically tied to things that are unique to Gelbooru.
