Hello,

the easiest way to change default avatar icons is to replace them in the following folder of the chat component using the same default avatars of your JomSocial:

root/components/com_jchat/images/avatars/jomsocial

There are 2 icons default_my.png and default_other.png used for default avatars that you can replace with your preferred ones. Please notice that the chat component does not distinction about sex for users because it's a feature of JomSocial so this is NOT possible to have different default avatars by sex.

Regards