The text color's serialized form: the style's, or by whether there is a fill to read on.
The line: the shape's own over its style's, field by field, with the style's color when the
shape states a line without one (an <a:ln w="…"> alone), as in Excel. undefined when
nothing states one.
The line width in points: stated, or Excel's implied width.
The fill, with the style's placeholder color substituted;
undefinedwhen nothing states one.