I’m separating each inspiration source, so here is the Welsh Museum garment with a bit more information.
COLLECTION AREA Social & Cultural Historyhttps://museum.wales/collections/online/object/e2ce99c3-462b-3da3-af0a-953e4f94008d/Dress/footer/
ITEM NUMBER 23.189.1
MATERIAL damask (silk) metal thread silver parchment flax (spun and twisted) silk (spun and twisted)
I don’t know if it’s possible to convey how much I love this gown.
A few people have managed to take photos when it has been exhibited and it does exactly as expected- the colour shifts to a more aqua tone.
British circa 1730 Teal Spitalfields Silk Court Mantua possibly belonged to Lady Rachel Morgan nee Cavendish daughter of the Duke of Devonshire. St Fagans National Museum of Walesttps://twitter.com/ladycecilynevil/status/1251855616487849985
For a pattern and a lot more information:
Arnold, Janet, A court mantua of c. 1740,Costume, London,#6, 1972, pp 48 – 52.