Definition of "watchet"

I was going by his Highneſs's order to my Lady Iſabella's chamber: She lies in the watchet-coloured chamber, on the right-hand, one pair of ſtairs.

1764 December 24 (indicated as 1765), Onuphrio Muralto, translated by William Marshal [pseudonyms; Horace Walpole], chapter V, in The Castle of Otranto, […], London: […] Tho[mas] Lownds […], pages 175–176

They him disarm'd, and spredding on the ground / Their watchet mantles frindgd with siluer round, / They softly wipt away the gelly blood […]

1590, Edmund Spenser, “Book III, Canto IV”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie

Firſt, the hethermoſt, in the changeable blew, and greene robe, is the commendably-faſhioned gallant, Evcosmos; […] The fourth, in watchet tinſell, is the kind, and truly benefique, Evcolos.

1600 (first performance), Beniamin Ionson [i.e., Ben Jonson], “Cynthias Reuels, or The Fountayne of Selfe-Loue. […]”, in The Workes of Beniamin Ionson (First Folio), London: […] Will[iam] Stansby, published 1616, Act V, scene ix, page 260

Shee, in a watchet weed, with manie a curious wave / Which as a princelie gift great Amphitrite gave

1612, Michael Drayton, “The Fifth Song”, in [John Selden], editor, Poly-Olbion. Or A Chorographicall Description of Tracts, Riuers, Mountaines, Forests, and Other Parts of this Renowned Isle of Great Britaine, […], London: […] H[umphrey] L[ownes] for Mathew Lownes; I. Browne; I. Helme; I. Busbie, published 1613, page 75

Who stares, in Germany, at watchet eyes?

1693, Decimus Junius Juvenalis, John Dryden, transl., “[The Satires of Decimus Junius Juvenalis.] The Sixteenth Satyr”, in The Satires of Decimus Junius Juvenalis. Translated into English Verse. […] Together with the Satires of Aulus Persius Flaccus. […], London: Printed for Jacob Tonson […]