Think about this for a minute and you can figure it out. If something is hidden, and you bring it out where the light can fall on it and everybody can see it, it's not hidden anymore. The saying means to expose hidden secrets or information. It can be used in a situation where you are "in the dark" because you just don't know something, and you can bring the knowledge to light by thinking or reading your books. It can also be used when someone is keeping secrets.
You can guarantee something.
flatter her to get something
Idiom
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
she really got the attention
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.
to make something stronger ,,
"Getting behind an idea" means to support or endorse that idea. It suggests that you are in favor of the concept and are willing to help it succeed.
Clockwork isn't an idiom that I'm aware of. The work means something that is mechanical, driven by old-fashioned gears and wheels. It can also mean something that runs as smoothly as if mechanical, or something repetitive and mechanical-seeming.
The idiom, "spice of life", means that you can do something to make your life more exciting. Do something that's daring, challenging, fun; something that's worth living for.