Online Flash Course - The Paint Bucket

The function of Flash's Paint Bucket is similar to the one found in other graphics software. You can use either a solid color or a gradient to fill objects with the bucket. However, since Flash is a vector based program, its paint Bucket also has a feature of closing any gaps in the objects' outline. (Note: Very large gaps cannot be closed automatically with the bucket. You have to do this manually using the Arrow tool).

The fill color lets you choose a solid color or a gradient.
Details of the Gap Size Selector modifier are presented in the image below.
The Transform Fill modifier lets you change the properties of gradient fills. For example, linear gradients are applied horizontally. In order to made a vertical gradient, you first have to fill the object with a linear gradient and change its orientation using this modifier.