The style of painting before the Franciscan movement was greatly influenced by the Eastern Empire. Byzantine iconographers followed a strict code of colour symbolism whereby blue was used to represent divinity while red represented humanity. The San Damiano Cross, a Syrian icon, has a predominance of the colour red. Even though Jesus dies in his humanity, here he is portrayed in his divinity as the glorified Christ, totally in control of the situation. In sharp contrast, the Blue Cross presents Christ as completely at the mercy of the external elements. Blood spills from his side. He is not resurrected, he is dead. Yet the phrase Rex Glorie ("The King of Glory") boldly appears on the reverse side of this two-sided crucifix.

At first the medieval viewer may have been confused by what appears to be a contradiction between the image itself and the words used to describe it. However, the plainness of the Blue Cross, as compared to the busyness of the San Damiano, answers the medieval quandary. This Christ speaks one simple truth, one simple message: this is true glory, to give one's life for another.

With the previous emphasis on divinity, the people felt distanced from a Christ who had already fulfilled his destiny, who had already passed beyond all suffering and was looking down upon their misery from the heights of heavenly glory. The genius of the Franciscan movement, beginning with this image, was to portray Christ as suffering. Christ died once for all, but he continues to feel the pain of our nails, our crosses, our deaths. Christ is found not in the heights of heavenly glory but in the glorified depths of sacrificial love.