Charles Sturt University School of Environment Sciences senior lecturer Andrew Hall said the brightness of colours was a “fluke” caused by smoke particles in the atmosphere. 

“Normally, we get a red sky during the sunset when the sun is low on the horizon so that’s quite normal, it’s called rayleigh scattering,” he said. 

“The smoke gave an extra type of scattering called mie scattering, where the particles in the atmosphere were the same diameter as the wave length of the light.

“The light was scattered about and gave a spectacular constant sheen of orange.

“It would be very unusual to get something like that just from clouds.”