Question

why sun appear reddish is known to every one ut please tell me why sun appear white when it is overhead in the sky​

Answer 1

When the Sun is high in the sky, the shorter waves, primarily the blue, strike air molecues in the upper atmosphere and bounce around and scatter. Hence explaining why the sky looks blue. Some people think that enough blue light is scattered out in the Earth's atmosphere to cause the Sun to appear slightly yellow.

Answer 2

Sun appears white when its overhead because there is no refraction at that moment as light rays incident at normal so there is no refraction or dispersion of light, so that's why sky appears white .