The channels of a colour string, or null where it is not a colour.
null rather than a throw, because asking whether a string is a colour is
the ordinary case and an exception is a poor way to answer a question. Use
isColor where only the answer matters.
The channels of a colour string, or
nullwhere it is not a colour.nullrather than a throw, because asking whether a string is a colour is the ordinary case and an exception is a poor way to answer a question. Use isColor where only the answer matters.