Wiktionary
a. 1 (context obsolete English) colourful. 2 Apparently true; specious; potentially justifiable. 3 (context now rare English) deceptive; fake, misleading. 4 That can be coloured.
Usage examples of "colourable".
But a stroll with a lord was worth more than that sacrifice, and every incident which helped to make a colourable case of confidential relations at Brandon—a point in which the good attorney had been rather weak hitherto—was justly prized by that virtuous man.
And lest his character be misconstrued (which would be deplorable) it may as well be stated now that he had not laid down upward of twenty thousand good golden guineas for a colourable Corot without having a tolerably clear notion of how he meant to reimburse himself if it should turn out that he had paid too dear for his whistle.
After being chosen as the leaders of the Ionians and of the other allies of Athenian origin, to punish the Mede, the Athenians accused some of failure in military service, some of fighting against each other, and others, as the case might be, upon any colourable pretext that could be found, until they thus subdued them all.
What I said was a colourable imitation of them, intended to appease the unreasonable rage of a tipsy man.
J'ai vecu, as I apprehend most of us manage to exist, missing all along the varied forms of destruction by a hair's-breadth, saving my body, that's clear, and perhaps my soul also, but not without some damage here and there to the fine edge of my conscience, that heirloom of the ages, of the race, of the group, of the family, colourable and plastic, fashioned by the words, the looks, the acts, and even by the silences and abstentions surrounding one's childhood.