Following yesterday's defocussed colours of Orion, here's something slightly different:
The Colours of Sirius
Here the colours don't reflect the temperature of Sirius directly – they're due to atmospheric turbulence changing the refractive index of the air.
That bends different wavelengths towards or away from the line of sight in a constantly changing way, creating this coloured "twinkling"
Also best seen by defocussing