What makes the moon look more yellow sometimes?

Question

What makes the moon look more yellow sometimes?

Answer 1

The atmosphere.

Same reason the sun looks redder when it sets then when it is high in the sky.  Differing atmospheric conditions means what color it looks may vary.

I you pay attention you'll note when you see a yellow moon it is low on the horizon.  If you check again in a few hours once it has risen you will see the silvery moon you are used to.

Answer 2

It's probably caused from reflected light from the Sun.

Since it's a yellowish star, it makes sense.