The background styles palette contains a list of styles Creator has provided:

The top left pane named Rainbow allows you to set multiple colours to create a gradient. The DW Blue and Solid panes uses only one colour for the background. All the other panes use a combination of two colours to create the visual effect.

Using the colour wells beside this palette you can change the colours used.

With most objects you can now chose to apply QuickStyles by selecting the QuickStyles button. This provides another palette of preset styles which combine background colour schemes with borders, textures etc to create a specific effects such as parchment or marble.