colourable

• colorable (American spelling)

From colour +‎ -able.

• (UK) IPA^(key): /ˈkʌləɹəb(ə)l/

colourable (not comparable)

1. (obsolete) Colourful.
2. Apparently true; specious; potentially justifiable.
   • 1603, Michel de Montaigne, chapter 8, in John Florio, transl., The Essayes, […], book II, printed at London: By Val[entine] Simmes for Edward Blount […], OCLC 946730821:

     Doth the master make any bargaine, or dispatch that pleaseth not? it is immediately smothered and suppressed, soone after forging causes, and devising colourable excuses, to excuse the want of execution or answer.

   • 1612, John Smith, Proceedings of the English Colonie in Virginia, Chapel Hill 1988 (Select Edition of his Writings), p.178:

     they told him their comming was for some extraordinary tooles and shift of apparell; by this colourable excuse, they obtained 6. or 7. more to their confederacie […].

   • 2003, Ofer Raban, Modern legal theory and judicial impartiality, page 83:

     These three examples have what may be called a 'colourable' claim for a public justification: they do not appear to us as checkerboard statues because, looking at the distinctions they draw, we presume the required justification does exist.

3. (now rare, sometimes law) Deceptive; fake, misleading.
   • 1590, Edmund Spenser, The Faerie Queene, III.iii:

     Glauce, what needs this colourable word, / To cloke the cause, that hath it selfe bewrayd?

   1. (law) In appearance only; not in reality what it purports to be, hence counterfeit, feigned.
4. That can be coloured.
   • 1811, Daniel Ellis, Farther inquiries into the changes induced on atmospheric air, by the germination of seeds, the vegetation of plants, and the respiration of animals, page 117:

     This matter, however, is not itself coloured, but is only capable of exhibiting colours, by the addition of other matters : and hence we have ventured to call it the colourable, rather than the colouring parts of the plant, by which we merely indicate its property of becoming coloured, but not its actual possession of colour.

   • 1978, A. G. Thomason, “Hamiltonian Cycles and Uniquely Edge Colorable Graphs”, in Advances in graph theory: Volume 1977, →ISBN, page 259:

     These results were discovered whilst investigating uniquely edge colourable graphs.

   • 1992, STACS 92, 9th Annual Symposium on Theoretical Aspects of Computer Science, edited by A. Finkel and M. Jantzen, page 397:

     A circle graph with no cycle of length four is colourable with three colours.

The sense "that can be coloured" is more common in American than in British English.

• Black's Law Dictionary, Sixth Edition.
• Oxford Dictionaries