In contrast, the few bits of gold used in the costume stand out and seem to shine, giving a touch of elegance to the painting. His garb seems to be too sophisticated and gaudy for a subject who I think would look more natural in simpler garments.
Most of the clothes are in shadow, however, as the artist is clearly playing with the use of light. Half of his face and most of his body are in shadow, as if the sunlight has shifted due to the passing of time since he first arrived. There is a single source of light which comes from the viewer's left and mostly from behind the subject. It starts right below the middle of the portrait and follows a linear path at a slight positive angle ending on the left side of his face. Perhaps it comes through a window several feet away which would limit the amount of incoming light reaching the subject. The light is gentle rather than sharp due to a filtering source such as glass and a great deal of the illumination is diffused on the background, which puts some of the subject in silhouette. With neither the subject nor the background entirely well lit, the light serves to blend them in some places, such as the top of the feather, and clearly define them in others, such as the subject's right shoulder. Brush strokes are clearly visible bordering the subject which helps distinguish him from the background.
The gold fringe of the subject's top and the gold on the hat provide a border for his face. Along with the light, they help draw attention to Rembrandt's face in the middle of the portrait. Looking outside of this frame, there are clearly items which help balance the painting. The feather in his cap provides vertical balance; without it, there would be too much empty space above his head. Providing horizontal balance is the subject's left arm. Upon further study, it looks as if it is too long, but it is clear that the painting would not be pleasing to the eye if it was shorter.
