Element’ary my dear Watt’son – The Mystery of Metamerism – Interior Lighting Design

The following is from Dr. Watson’s biographies of his friend Mr. Sherlock Holmes:

We had been called in to investigate the strange occurrence of changing paint color in an 1890 Victorian stick-style-home. There was a bit of haze and the moon shone down on the entry.

As my friend, Mr Sherlock Holmes, entered, his deep-seated, keen eyes immediately perceived that the room had a curious white-blue tone. Following after him, I had the fact pointed out to me.

“This case is of course lucid, but it does have some interesting features,” remarked Holmes.

“How do you mean?”

“Watson, I really would be at a loss what to do without you! Your predictability is like the Rock of Gibraltar. Now, you do see the paint-can sitting in the corner of the room labeled “Butter Yellow?”

“Yes.” Furthermore, I notice that he has stood an excellent, fastidiously rolled umbrella against the counter, with the refined air of a certified color professional.

“Really, Watson, look up and you will see a spiral compact florescent bulb screwed into the ceiling mount lighting fixture causing this white-bluishness. I should have thought even you realized that it is common knowledge that the type of bulb has complete bearing on wall paint color and to the case at hand.”

I apologized.

“Your apology is accepted, Watson. Have you noticed the peculiar flattened object that adorns the floor in the middle of the room?”

I bent down and took up the object in question.

“It is just a spent light bulb box. I fail to see how that can be of interest,” remarked I.

“You do? Come, come. You know my methods, Watson; apply them.”

I looked at the box and on it’s side in big bold print it read Halogen 3300 Kelvins. I imagined the whitish luminosity that had filled this room moving the wall color further towards cool lemon than the warmer butter. Yet, it must have been emitting a high heat, as is the case with Halogens.

“Apparently, this was the original bulb that lit the room” said I.

“Excellent, Watson! What is more, where your eyes are presently resting on; observe that fingernails have bored into the right-hand edge of the box.”

“There must have been a victim of a strong emotion,” observed I.

Holmes smiled a bit sadly, as if his cold, strange intellect had for once been impressed by reflections of a more compassionate nature. “Indeed he was! Would not the original Halogen bulb have brought out tones shifted to cool in these walls , Watson?”

I glanced again at the bulb box.

“Quite so! Said Holmes, And what other types of bulbs would have an effect on this wall color?”

It had not occurred to me to consider this matter before. Now I looked to where the paint can stood, and there in the same corner were three additional boxes; one labeled LED, another Incandescent, and the third Carbon Filament, “but I really do not understand…” I fell silent as an icy emotion of terror permeated every inch of my body. I looked around at the pathetic, blue hue in the room.

Holmes nodded. “God help us!” he said. His face was pale, showing that even he felt some of the dread that the situation inevitably evoked.

The hall door had slowly opened, and we saw a lamp-lit wall with a very warm yellowish hue. The lamp contained one carbon
filament bulb with quad loop 40 watt filaments within. We stood observing the long casting orangish shadows with sweat beading on our brows as the room was heated with color.

We stepped forward into this room, and an extraordinary change came over us. The shadows swelled in size.

“Quick, Watson!” cried Holmes, moving backwards without taking his eyes off of the walls. I hurried to unholster my revolver while my eyes peered into this deeper, more sunflower than butter-yellow space.

“What on earth is this, Holmes?” said I, while still brandishing my weapon.

“I think the remaining two bulbs may throw some light on the matter.”

I proceeded to read the two boxes and opened them. The first bulb was a 40 watt standard incandescent and I screwed it into the lamp socket. What surrounded us once again was a natural Butter-Yellow tone. We stood in wonderment.

“There are some undesirable side affects with bulbs Holmes explained, and it is not without danger of a kind to wall color selections. In particular the strange delusion of the room color being too cool or too warm. This distorted perception explains why I now apply the remaining LED bulb to take every possible precaution in choosing the right bulb for the wall color.” Holme’s words spoke of an obscure scientist who was striving in some unknown way for the secret of rejuvenescence and the elixir of life.

The 40 watt incandescent bulb burned to the touch as Holmes unscrewed it and replaced it with the LED. He looked with an incredulous eye at the hint of blue-green cast within the room now, with a calm assurance and power within his manner. He stood before me like a conjurer performing a trick.

“After all Watson,” said Holmes and relit his pipe, “I rather fancy that we shall now know a good deal more about how light bulbs affect wall color.”

Excerpts from Arthur Conan Doyle’s “Adventures of Sherlock Holmes, The Hanging Man and The Jumping Man” are included in the above.


Metamerism, is the effect of light on colour. Lighting can be either warm or cool, depending on the source. Incandescent lighting (the kind given off by traditional lightbulbs) falls on the warmer side of spectrum and enhances red and yellow tones. Florescent or LED lights are cooler, bringing out blues and greens. Natural sunlight is considered the ideal light source because it is neutrally balanced between warm and cool. But even here you have to be careful. Colours will change throughout the day depending on the intensity and direction of the sun’s rays.


Light Bulb Comparison Chart:


Wikipedia on :