First — why does the color of the Moon change? It's because the light needs to travel a longer path, and shorter wavelengths (blue and violet colors) are scattered away. So red and orange ones become more dominant.

Second — why does its size look different? Actually, we don't really know. People have debated this for centuries. One of the famous hypotheses is the comparison hypothesis: when the Moon is on the horizon, we can compare it to trees and buildings. But when it's high up, we compare it to darkness. So it just feels smaller.