[imsc] Pull Request: Remove background-color feature per removal in TTML2

palemieux has just submitted a new pull request for https://github.com/w3c/imsc:

== Remove background-color feature per removal in TTML2 ==
Closes #255 

See https://github.com/w3c/imsc/pull/295

Received on Monday, 15 January 2018 19:56:15 UTC