Range: six character hex color value
The color of the background behind the generated graphics. Ignored if this theme is being
used with the Matte or Displace effects, which
only draw the graphics themselves. Typically bound to a Picker control.
backcolor: six character hex color value
editable: comma delimited list of property names
font: valid font id
forecolor: six character hex color value
id: single word string identifier, starting with a letter
length: floating point number (frames)
symbol: a valid SWF URL, followed by an ampersand and class name
text: any string
textsize: positive number (percentage of display height)
type: the string 'theme'