so that Dante ... so fire-colour she was, all through
Note from the Letter Charitas by John Ruskin

'Our queen' is the lady who gives her name to this letter of 'Fors Clavigera': Charity. The three theological virtues (Faith, Hope and Charity), together with the four cardinal virtues, take part in a divine pageant which Dante witnesses in the Earthly Paradise. Charity is described, in the words Ruskin quotes in his footnote, as

'so red that hardly would she be noted in the fire' ( Purgatorio , xxix, 122-3).