A beautiful wedding anniversary card picture background could be described as follows: A captivating blend of warm colors, perhaps a sunset or sunrise, casting a soft glow over a serene landscape. The foreground might feature a delicate arrangement of flowers, symbolizing enduring love. In the center, there could be an elegantly designed space for heartfelt messages, bordered by intricate patterns or motifs that reflect the joy and sanctity of marriage. The overall design would convey a sense of celebration, love, and the passage of time, making it a perfect backdrop for a wedding anniversary card. Please note that this is a textual description and the actual design may vary.