We will start with the You Are Here, that is in a language file which you can modify or create a new version for a different language.
Open administrator>language>en-GB>en-GB.plg_system_jat3.ini and you will see the following near the top. Modify the bit in red as required.
YOU ARE HERE=You are here
SKIP TO CONTENT=Skip to content
HOME PAGE TITLE=Welcome to the Frontpage
Same goes for other language strings.
Onto the header colours, take a look in the templates>ja_social>core>themes>**************>color.css for the different colours for the different theme variations. Replace the ************** wit the colour of your choice.