The type of light under which color is viewed makes a tremendous difference in how we perceive a particular hue.
Considered the ideal light source, natural sunlight maintains a neutral balance between both the warm (yellow case) and cool (blue cast) ends of the light spectrum. Northern light is the coolest, while light from a southern exposure is the strongest. Here, direct sunlight provides the truest rendition of the colors in this room.
Natural sunlight is not consistent. It changes from sunrise, to noon, to late afternoon and dusk. The intense golden rays and subsequent distinct shadows of a sunny, late afternoon have a profound effect on the colors in this room.
The color rendition appears warm under incandescent and halogen lights, where reds and yellows are enhanced and blues and greens are culled. Under the cool cast of fluorescent lights, blues and greens are enhanced, while reds and yellows are muted.