Or with some general wide pants, pants above the knee.

If the trousers match red, your coat looks good with white.

In one place, your legs are white. No, white shoes will definitely look good.

I don't think it should match gray. Gray itself is not a bright color system, and the red, white and blue of shoes are brighter. If you wear gray pants, you can't show the characteristics of pants. Of course jeans are very versatile.