Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <style> a:visited { background-color:yellow; } </style> </head> <body> <a href="../default.htm">W3Sschools Home</a><br> <a href="../html/default.htm">W3Schools HTML Tutorial</a><br> <a href="../css/default.htm">W3Schools CSS Tutorial</a> <p><b>Note:</b> The :visited selector style links to pages you have already visited.</p> </body> </html>
Result:
W3Schools.com - Try it yourself