Red letter day
A red letter day is any day of special significance or opportunity. Its roots are in classical antiquity; for instance, important days are indicated in red in a calendar dating from the Roman Republic.
Read on WikipediaCeremonial red ink, used for the dates that get circled on the calendar.
Red-Letter Day is a vivid pink, close to red.
It can be described as vivid, vibrant, strong and bold.
Set in white, because white reads best on it.
A red letter day is any day of special significance or opportunity. Its roots are in classical antiquity; for instance, important days are indicated in red in a calendar dating from the Roman Republic.
Read on WikipediaA day is the time period of a full rotation of the Earth with respect to the Sun. On average, this is 24 hours. As a day passes at a given location it experiences morning, afternoon, evening, and night. This daily cycle drives circadian rhythms in many organisms, which are vital to many life processes.
Read on WikipediaNoun