Once you've changed the color of your chat widget, it will affect these elements: Visitor Form outline, Submit button, Widget header background color, The border of your department and its box border, Send message button background, Focused message box border color, The Copy Code in the Coupon window, Visitor messages, End chat button and Background of prompt & new message in minimized state.
The widget title & subtitle will display like how the admin has set in the Settings > Widget Customization until a chat is initiated (same goes for branding logo):
Widget title & subtitle would be replaced by agents name and avatar with selected department when inbound chat is initiated.
Outbound chat will not have department.