A DTD not under my control includes colors specified with tags like
<option name="backgroundColorHex" value="292d3e" />
No prefix there, but as far as I can tell there's no way to make the plugin pick these up without editing the file. Would be a nice addition to allow for a custom setting allowing to transform the captured value, primitive solution by just modifying the string, not sure if there'd be much need for numeric conversion of individual channel values!