You can set up booking areas where your agents can book your products directly. Here is information on how to set up booking agents if you haven't done so yet. If you haven't created a booking area for your agent yet, you can find information on how to do so here.
Customise your booking area theme
Select "Contracts" > "Booking Area Themes".
Either edit an existing booking area theme by selecting the name of the theme or add a new one by clicking on "Add".
You can now customise the colour of your booking area as much as you like.
Remember to save your changes.