Hello Nick,
If you are in rush following link may be helpful for you. (Bottom of the page you will find more about mt0 mb0 bt0 bb0 no-shadow elements.
http://dante.swiftideas.net/documentation/#swift-page-builder
On the other hand, you may try to use Page Builder asset Text Block (Full width) for arrow shape on the bottom. For background colour you can use Theme Options > Asset Background Options and personalise one. And select the option from text block asset.
Find the attachments, may help.
P.S : Staff will reply your questions in the morning. I hope this help for now.