Justify why the brewster angle for a transparent medium is different for different colours of lights?

Brewster’s law states that, the tangent of polarising angle of incidence to the transparent medium is equal to the refractive index of the medium

$tan ,{{i}_{p}}=mu$

ip- polarising angle of incidence

ip= tan–1 μ

The angle is depends on the refractive index of the medium.

Since,

$mu =frac{c}{v}=frac{speed,of,light,in,vaccum}{speed,of,light,in,medium}$ $mu =frac{c}{v}=frac{gamma lambda }{gamma lambda medium}$

refractive index of medium function of wavelength of incident light, therefore the angle of polarization ip will vary with respect to colour of the light.