和彩虹有关：
chase rainbows做白日梦
Chasing rainbows won't get you anywhere.

和风有关：
sail close to the wind冒险
If you believe what he said， you are sailing close to the wind.
know which way the wind blows了解情况
He never tells his thoughts until he knows which way the wind blows.

和雪有关：
be snowed down工作太多做不过来
I've been snowed down by my work！
white as snow纯洁无辜
The accused didn't commit the murder，he is as white as snow.

和天气有关：
fair-weather friend泛泛之交
A true friend is the one who shows up when you are in trouble, a fair-weather friend is the one who shows up when you are in happiness.