Danger in Chinese / Japanese...

危 means danger, peril, or “to endanger” in Chinese, Japanese, and old Korean.

If you live a dangerous life or want to subtly warn others that you are a dangerous person, this may be the selection for you.

This also means “danger” and sometimes “fear” in Japanese and Korean but is seldom seen outside of compound words in those languages (as a single character, it's kind of like an abbreviation for danger in Japanese and Korean). 危 is also a rather odd selection for a wall scroll anyway. It's only here because people search for danger on our website.

危機 means crisis in Chinese and Japanese.

Separately, the first character here does mean “danger” or “to endanger,” and the second character can mean “opportunity.”

However, I want to debunk a myth that was propagated by some westerners who did not have a clear understanding of Asian languages...

While often, Chinese/Japanese/Korean compound words (words of two or more characters) are the sum of their parts, this is not always the case. The compound is often understood with a completely different meaning than the two characters individually.

Many have said that the Chinese/Japanese/Korean word for Crisis is made up of the characters for “danger” and “opportunity.” 危機 is true when phrased this way.
However, it's not absolutely correct to say that “danger + opportunity = crisis” in Asian cultures.

English example:
If I tell you that...
Bovine creature + Guy behind the plate in baseball = Locomotive train protection
...you would think I was mad. But consider that “cow + catcher = cowcatcher,” which is the device that used to be found on steam engines to protect them if they hit an animal on the tracks. When we hear the word “cowcatcher,” we don't separate the words into their individual meanings (necessarily).
The same is true with the word for crisis in Chinese/Japanese/Korean. While you can separate the characters, few Asian people would automatically do so in their minds.

The final answer:
It is a half-truth to say, “danger plus opportunity equals crisis” in Chinese/Japanese/Korean. Use this statement and concept with caution.

Also, the second character can mean “secret” or “machine,” depending on context so I guess you have to say “a dangerous machine = crisis” or “danger + a secret = crisis.” Both of these are only slightly more ridiculous than the first premise.

PS: 危機 is probably not a great word for a scroll unless you have a special use for it.