You can create mood boards of colours and pictures within the app. Simply click on the "+" icon in the top right corner when you are looking at a colour and either select an existing board, or create a new one.
From the Boards main menu, you can see a list of all your boards, view and edit them. You can also create new moodboards by clicking on the "+" icon in the top right corner on the Boards page.
You can also re-arrange boards, as well as change the layout between different grid sizes to suit your needs.