Inline Styles

The C/S Specification has this section:

It is also possible to avoid importing an external style sheet and include
the styles directly in the WebVTT header. Here is an example:


WEBVTT
Style:
::cue {
  line-height: 5.33vh;
  font-size: 4.1vh;
  font-family: monospace;
  font-style: normal;
  font-weight: normal;
  background-color: black;
  color: white;
}
##
Kind: captions
Language: en-US

I don't see much discussion of inline styles in the WebVTT spec.  Is it
also possible to have named styles defined inline like this?

::cue(c.white) {
  color: white;
}
::cue(c.red) {
  color: red;
}


Thanks,
David