If Sherlock had the thought to spare, he might have found that particular shade of yellow rather obnoxious. The fact of the matter was, however, that he did not give a whit about the color of the walls, the carpet, the comforter, the desk—these were all trivial.
John's senses, however, were still quite capable of being offended.
And good God were the walls heinous.
If he had to share a room with Sherlock tonight (which was fine, by the way; it was just that he was a terrible or entirely nonexistent bedmate when on a case), John would prefer that it was in a room that was less yellow. The most practical reason being that the doctor had a feeling Sherlock would be up all night and refuse to turn off the lamp, meaning the walls would practically glow, and he had enough trouble sleeping in the first place.
The least practical reason being, of course, that this was an ungodly color.
"I don't suppose you plan on sleeping?" John inquired, tucking his change of clothes neatly away.
Sherlock was bowed over the desk. "No. Too much to do." He drew a sack from his pocket and emptied its contents, clinking, on the wooden surface.
John turned down the covers (a cream that clashed terribly with the walls, but at least they weren't yellow). "Thought not." The doctor peered around Sherlock to watch his clever fingers shuffle a dozen or more shards of glass across the desk, arranging and re-arranging them. "What's that?"
"Hush."
He rolled his eyes and crept around to get a better look, careful to stay out of the detective's light. The shards varied in length and shape, some barely two centimeters across, others at least ten.
"This is the key to finding the thief." Sherlock said at last, hands never resting. "The glass from the broken window was arranged in a very particular shape before he fled, but the first person to discover the scene disturbed the pattern before authorities could get a look at it."
"And you took them because you think the victim disturbed them on purpose—that she's hiding something?"
Sherlock's eyes flashed like the pale center of flame. "Precisely. You're learning well, John." The smallest flicker of a smile, and then he was lost in the shifting glass patterned by his fingers, glinting in the lamplight.
John almost wished, selfishly, that the detective would indulge him a little more with something as simple as a touch, but knew better than to hope for it. Until the case was over, Sherlock—more than would not—simply could not be distracted, and as much as John might like the detective to join him after the puzzle was finished, if only to be assured that he wouldn't disappear without waking the doctor before morning, he knew it was improbable. And even if Sherlock did join him, it would be a restless night as the detective did not know how to stay still when the thrill of the chase was upon him.
So, the doctor retired alone and closed his eyes against the glare of the walls (damn bloody yellow walls), comforted by the sound of glass sliding over wood, and the image of Sherlock's fingers dancing across it.
John would wake when the sound ceased, and be glad he had not gotten undressed, else he would have fallen too far behind the detective on his rush into the street for comfort.
He wouldn't have it another way.