Given the following Path I would expect the resulting diamond shape to get filled with red but it doesn't. Am I missing something here?
<Path Data="M59.351001,42.182 L30.783001,84.351998 M0.75000094,43.78 L30.783001,84.45 M59.351,42.182 L29.318001,0.74999998 M0.75000094,43.78 L29.318001,0.74999998"
Margin="254.7,207.333,325.199,187.467" Stretch="Fill" Stroke="#FFA91515" StrokeThickness="1.5" d:LayoutOverrides="VerticalAlignment" Fill="#FFFF2300"
Thanks.
It looks like you have just drawn four straight lines that happen to look like they form a closed path, while they actually don't. If you use the Direct selection tool, you can actually drag these lines around.
How do I know this? You have four Ms in Data. An M denotes the start of a new line.
You will need a closed path to be able to "fill" it. Try using the Pen tool instead to create a closed path.