Chat colors can be customized in the Settings -> Live -> Chat page:
You can use any of the pre-defined chat themes or change the colors individually so they match your branding guidelines. After changing the color, the preview automatically shows how the chat will look like for the end users.
Note, the moderator chat cannot be customized and is always presented using the Console theme.
Terms and conditions
You can append additional terms and conditions which are presented when users choose their name on the chat.
They are then shown above Screen9's terms: