This rule will suppress the line, instead of coloring it:

$ echo 'default rule "FRANCISCO" --> suppress' >> ~/.clogrc
$
$ clog < hamlet
BERNARDO Whos there?
BERNARDO Long live the king.
BERNARDO He.
BERNARDO Tis now struck twelve, get thee to bed, Francisco.
BERNARDO Have you had quiet guard?
BERNARDO Well, good night.  If you do meet Horatio and Marcellus, The rivals of my watch, bid them make haste.
[31mHORATIO[0m Friends to this ground.
[30;44mMARCELLUS And liegemen to the Dane.[0m
[30;44mMARCELLUS O, farewell, honest soldier: Who hath relieved you?[0m
[30;44mMARCELLUS Holla. Bernardo.[0m
BERNARDO Say, What, is Horatio there?
[31mHORATIO[0m A piece of him.
