The colors red and green are often associated with Christmas because they evoke a sense of warmth and joy. Red symbolizes the love and generosity of the holiday, while green represents the vitality of nature and new life. Together, the two colors create a festive and celebratory atmosphere that is perfect for the season. Additionally, red and green are complementary colors that create a visually pleasing contrast when paired together, making them a popular choice for decorations and gift wrap during the holiday season.