If you can offer a solution, you are encouraged to try.
It is not an idiom because you can figure out what it means. If something disagrees with you, then you don't like it or it makes you feel bad. This metaphor means that you don't like the climate.
The idiom "made his heart feel heavy" suggests that someone or something has caused emotional pain or sadness. It implies that the person's heart is burdened with negative emotions such as guilt, sorrow, or regret.
The full idiom is "Free things can be very expensive". An idiom is a turn of phrase that seems to mean nothing, but requires thought to unravel. The reason free things can be expensive, is that they're generally free because they're not very useful.
You can guarantee something.
A worry or anger seems to sit on your chest and make you feel heavy. When you tell someone how you really feel, you're getting it off your chest.
If something is a let-down, it is a disappointment. The image here is that you have built up your hopes. You are looking forward to something, and when it does not occur, you feel as if you have been let down.
Idiom
flatter her to get something
It depends on how you use it. If you mean literal colors, then it's not an idiom. If you say something like "It's all there in black and white," then it's an idiom meaning that something is printed.
to want to do something; a wanting to entertain oneself
Eternal isn't an idiom. It's a word. Idioms are phrases that seem to mean one thing but mean something else.
It's not an idiom - it means a cup with some tea in it. NOT your cup of tea, however, is an idiom - it means that something is not to your liking or preference.