When someone feels shy or embarrassed, their face, and especially their cheeks, may temporarily become red or rosy-colored. We call this "blushing" in English. As we become older and more confident and experienced in life, we tend to blush far less. So, blushing is often associated with younger people, and a first blush would mean the first time someone feels shy or embarrassed. When wine is being made, some vintners mix the red and white wines, creating a pale rose-colored wine, also called a blush wine. The first batch of the season is the first blush. Today, this term has become an idiom: "At first blush" can be used in any situation where we want to describe an initial reaction or assessment of some issue or situation. It also indicates that we hope to gather more facts about this issue or situation later.