Updated : 2021
A quick guide to dashes / feathering / fill and stroke properties for the custom shapes in Photoshop tutorial
Changing colors of a shape layer
Stroke color for shapes
Dash styles
Feathering of paths
Sadly, the gap / dash etc are only of use when you are using a layer and will not work with pixel / fills - would love to see that but I doubt if that will ever happen.
You can combine multiple layers with different strokes and create many different and interesting combinations.
You can change the fill color by selecting the shapes tool as well as the shape and then going to the top of the application and changing the filll color - it can be set to a solid color and it can also be set to a gradient or pattern. You can also, with the more recent versions, change the fill color via the super useful properties panel
You can see the fill and stroke via the options bar for shapes in Adobe ® Photoshop. The stroke options are beside the stroke dropdown. You don't even need to have a fill as the fill can be set to "no color".
The stroke feature can be used to create many interesting line designs with any of the presets. The easiest way to explore the different stroke settings is probably to select some very basic artworks such as a circle and square (especially if you want to understand corners option as the corners only appear when you have actual corners).
The caps are interesting and change the way the dashes project out from their semicircular etc setting. The alignment is useful if you wish to align inside / center etc.
You can create your own presets which can be saved as well as deleted (select the stroke option preset and right side menu of the stroke options to delete them) - you cannot delete the factory supplied items though.
Strokes can be applied using solid color and gradient and patterns in the same way as the fill.
You can also now add a feather via the properties dialog in Adobe ® Photoshop ® for use with the vector artworks and that can be a great way to add a quick blur to any of the artworks / presets
Personally, I wish Adobe would add even more to the shape such as an appearance panel (such as in Adobe AI) so additional fills and strokes could be added the preset (again, this is where the new features of the layer styles comes to the fore with multiple strokes available). Would love to see something like live effects and round corners as well as perhaps width profiles added to the artworks. The workaround for that is to copy the artworks from Illustrator