the world > matter > properties of materials > temperature > heat > burning > fire or flame > [adjective] > of the nature of or resembling flame > of bluish colour (4)
Of a flame, flash, etc.: blue or blue-white in colour.
Sulphur-coloured; sulphur-yellow. Also, of the bluish colour of the flame with which sulphur burns.
= sulphureous, adj. 4. Also adv.