Definition of "colourless"

The servant to whom he put this question was a young fellow with chubby cheeks, small, dull eyes, and a round chin, covered with a colorless down.

1867, Ivan Sergheïevitch Turgenef [i.e., Ivan Turgenev], chapter I, in Eugene Schuyler, transl., Fathers and Sons […], New York, N.Y.: Leypoldt and Holt, page 1

Behind him the hills are open, the sun blazes down upon fields so large as to give an unenclosed character to the landscape, the lanes are white, the hedges low and plashed, the atmosphere colourless.

1891, Thomas Hardy, Tess of the d'Urbervilles, volume 1, London: James R. Osgood, McIlvaine and Co., page 14

The wide prospect up stream was grey and lowering, the long still-distant waterfront of Dundee, and the Fife shore were alike colourless, and there was ample evidence of rough weather not far ahead.

1947 January and February, O. S. Nock, “"The Aberdonian" in Wartime”, in Railway Magazine, page 7

They cannot, of course, assume a colourless position because they cater to the radical rank and file and would be branded renegades.

1926, David Joseph Saposs, Left Wing Unionism: A Study of Radical Policies and Tactics, page 73