why does light acquire a diferent light if it is passed through a different coloured transparent substance
because the transparent substance changes the wavelength of the light
White light is actually made of all the colors of the visible spectrum, which ranges from red to violet. A prism or a rainbow shows these colors by sorting light according to wavelength. Light passing through a completely transparent medium, like a pane of glass, will not show much difference. Light passing through a colored medium will allow mostly light of the color's wavelength to pass through, so you see that color. Light reflected off an object shows a color if the object reflects light of that frequency (wavelength). The colors have to be there first. Color is not acquired by light.
It doesn't aquire anything. Light is made of of energy in different wavelengths. As it passes through a coloured medium, the light of that wavelength is absobed.
