The Darnley portrait

 The Darnley portrait was most likely painted from life around 1575–6. This portrait is the source of a face pattern called "The Mask of Youth," which would be used and reused for authorised portraits of Elizabeth into the 1590s, preserving the impression of ageless beauty. It is thought that the artist is Federico Zuccari, or Zucaro, an "eminent" Italian artist, though not a specialist portrait painter, who is known to have visited the court briefly.

The Darnley Portrait features a crown and sceptre on a table beside the queen and was the first appearance of these symbols of sovereignty separately used as props (rather than worn and carried) in Tudor portraiture, a theme that would be expanded in later portraits. Recent conservation work has revealed that Elizabeth's now-iconic pale complexion in this portrait is the result of the deterioration of red lake pigments, which has also altered the colouring of her dress; the oranges and browns would have been crimson red.

Sources:
The Real Tudors: Kings and Queens Rediscovered, Tarnya Cooper and Charlotte Bolland

Gloriana: The Portraits of Queen Elizabeth I, Roy Strong, p. 85