Question

at noon sun appears white what near the horizon it appears red why​

Answer 1

At noon sun is directly overhead (at the least distance from the observer) so white light rays reach the observer without being much refracted. Hence,it appears white

While at dawn or dusk...near the horizon
Due to large wavelength of red colour it is refracted least while every other colour of white light (VIBGYOR) is much lost.

hope I made you understand :)

Answer 2

The light is least scattered at noon. .