Depending on what elements are selected at a given time, the Fill Tool, Surface Decor Tool, Textile Tool and Ribbon Tool may display different options.
If a tool is opened that caters for views ( Fill Tool or Surface Decor Tool ), and any multi-faced object ( cake or board ) is selected, the view options will be shown. It looks like this...
This will control where any adjustments are applied on a selected cake or board. For example, if SIDE is active, the action taken from the tool, whether it is changing a colour with the Fill Tool, or applying a Surface Decor with the Surface Decor Tool, will only be applied to the sides of the cake/s or board/s that are selected.
If the tool allows for it, and any multi-layered SVG element is selected, the Object Layers options will appear. It will display a colour swatch for each layer that exists on the selected element.
This will control where the adjustments are applied on a selected element. For example, if a butterfly with 4 layers is selected, there will be colour swatches for each layer. To adjust each layer within the butterfly, each colour swatch can be selected to set that particular layer as the target before making the adjustment with the tool.