Some customers and testers wish multiple colors for annotations. I guess it could be useful - but - the color selections have to split and defined to the session users. Otherwise the users could get confused to see, who've drawn the annotations. Maybe it would be more useful to use pre-defined symbols like a green check mark or a red stopp sign instead of drawing these symbols in different colors. Or maybe user 1 get access to 3 different colors to toggle between to draw different annotations and any other user get other 3 different colors and all users have access to symbols like arrow with instanced numbers and well known symbols like OK check mark, Stopp, Warning Sign(s), Circle / Elipse, etc.