To help you get started on this question, let's review some of the basics about the Book of Kells. This illuminated Gospel book was probably inscribed and decorated around the year 800. The four Gospels are handwritten in Latin in the “insular majuscule” style of handwriting, a round-lettered style. The book, which is made of vellum (calfskin) and consists of 340 folios (or sheets), likely served as a ceremonial text used on special occasions. It may have been created completely at Iona, Ireland, or partly there and partly at Kells, where it was brought after a Viking raid in 806.
The Book of Kells is lavishly decorated in an extremely elaborate fashion. It blends Irish-Celtic traditions with Anglo-Saxon elements to create brightly colored, intricately drawn patterns and large, stylized figures.
Let's look at the illustration that refers to the birth of Christ. The Virgin Mary sits at the center of the illumination with the infant Jesus on her lap. She is surrounded by angels. The images are stylized rather than realistic with proportions being somewhat “off” as seen by the modern eye. The colors are bright and varied. The page surrounding the human figures is filled with geometric and interlaced patterns that are intricate and lead the eye through almost an artistic dance. Images of animals and humans are interwoven into the patterns. The figures' garments are also heavily patterned and brightly colored. Mary's head is surrounded by an elaborate halo with three crosses inside, pointing to her Son's sacrificial death.
Nearly ever page of the Book of Kells is illuminated in some fashion, at least with colorful letters and small patterns and creatures intertwined into them. The most stunning pages, though, are the ones that contain a full page of illumination.