colour (n.) 2
good ground, convincing reason, excuse
Cym III.i.51 [Cymbeline to Lucius] Caesar's ambition, / Which swelled so much that it did almost stretch / The sides o'th' world, against all colour here / Did put the yoke upon's
H8 I.i.178 [Buckingham to Norfolk, of Emperor Charles] Under pretence to see the Queen his aunt - / For 'twas indeed his colour
JC II.i.29 [Brutus alone, of Caesar] the quarrel / Will bear no colour for the thing he is [i.e. there is no good ground for making such a claim in his present condition]
MW IV.ii.151 [Ford to all, of his search for Falstaff] If I find not what I seek, show no colour for my extremity