Regulus always hated green. All shades of green.
Phthalo green
Regulus's earliest memory was burrowed into him as vividly as the feeling of Mother's claws burrowed into his shoulder. He was four. No taller than the aged house-elf that stood in the ballroom of Grimmauld Place. It was just the two of them. House-elves didn't count as thems, just its, and it was trembling from ailments of time that impaired its ability to serve.
"Retirement is an honor," Mother crooned. The hand not clutching his shoulder pet his fine hair in a delicate manner in stark contrast to the fingers painfully digging into the space below his bone. "It served the halls of House Black well and now its head shall be preserved on the walls forever more."
Mother stilled her hand on Regulus's head. Her wand arm rest lazily on his sore shoulder, pointing sinisterly at the house-elf.
"Sulphurium Maledictus," she whispered into his ear, deliberate, pedantic. A short flash of brilliant blue hit its chest. It let out a soundless gasp. The tremors increased. But it did not cry. Its face twisted in perverse determination. Blue spread out from under the worn tea towel, creeping like little snakes along its life lines. Bruising, little serpents that left ripples until every part of its body was dyed blue. It gave a violent shudder and released such a wheeze that Regulus was sure he saw its soul escape. Souls smelled of rotten eggs apparently.
Mother's wand quickly slashed across his vision. An odd gurgle followed. Regulus unconsciously flinched and tried to turn his head. But Mother's hand held his head steady, unforgiving talons pinching his scalp.
A clean cut split a partial opening across the house-elf's neck, releasing phthalo green blood. A river ebbing out to form a dark green lake at its feet.
"Sirius should be here for this ceremony, but he has heir lessons today, and I simply could not condone another tea tray rattled by Kritter a moment longer." Mother continued to wax eloquent the mechanics that Great-however many-Aunt Elladora devised to better mount a house-elf; how great a privilege that Regulus, her sweet spare, was granted the opportunity to participate; the tedium that redecorating the halls to fit the new ornament would be but indeed, needs must–
Warm droplets speckled Regulus's face and hands.
The house-elf's body fell knees striking the viscous pool at its feet, the rest of it slumping into an unnatural kneeling position. Its head lolling to rest on its chest as its body remained impossibly upright, the black-green still slowly streaming out.
Mother released her grip on Regulus's head and went over to the crumpled corpse. Then, Mother gripped the top of its head, with the same hand that held his head Regulus noticed numbly, unable to look away. With another quick slash of her wand, Mother completed the cut. The body fell forward, like strings finally cut on a macabre puppet. Another splash on Regulus. Show over.
"Run along and wash up for dinner, dear." Mother examined her handiwork. "The rest won't take but a moment."
Regulus turned and left the ballroom, slowly, stiffly. Gentlemen did not run. Gentlemen did not cry. But his feet were not gentlemen when they broke into a run on the stairs. And his eyes were not gentleman when they cried upon seeing his face in the mirror, pale green painted with dark green ichor. Standing under the shower, still clothed, heart beating a wild tattoo in his chest, Regulus stared at the facsimile of green rivers ran off him and into the bathtub drain.
Long after the water ran clear, Kreacher came into the washroom to finish bathing Regulus. Kreacher led the sedate Regulus down the stairs by the hand. Regulus reached the final set of steps down, but he could not budge another inch.
Kreacher looked back, traces of a frown ghosting on the corner of its mouth. Its eyes followed Regulus's horrified gaze. A wide toothy grin broke across its face.
"Such honor," Kreacher beamed, nodding vigorously, ear flapping with unbridled enthusiasm. "Kreacher's mother lived to serve the noble house of Black. Kreacher lives to serve the noble house of Black. One day, Kreacher will have Kreacher's place."
Its didn't have mothers. Kreacher had a mother. His mother's name was Kritter. And her head now hung on a plaque in the hall. A wood plaque still freshly stained green with sulfur enriched blood.
Regulus tightened his grip on Kreacher's hand. He vowed he would never let that caring hand suffer.
Emerald green
Sirius did everything well. Sirius the heir was Mother and Father's pride and joy. At nine, Regulus was just happy to not suffer Mother's sharp tongue. Sirius was blessed with all of Father's fine features and Mother's wicked wit, while Regulus had an odd amalgamation of Father's wide features set on Mother's narrow pinched face. Regulus was cursed with a timidity that did not befit the House Black, while Sirius' silver tongue could charm snakes off the furnishing.
Sirius's greatest talent, though, was his penchant for mischief. Sirius's favorite use of his talent was being contrary to their Mother. If Mother required dress robes, Sirius wore none and left his shirt untucked. If Mother liked cats, Sirius adored dogs. If Mother found Mudbloods boorish, Sirius thought Muggles were fascinating. Yet, no matter how much he ran the halls or stomped on stairs, how cheeky he spoke to Father or disrespected Mother, how many priceless treasures he defaced or heir lessons he skived, Sirius was heir so never to be touched.
After all, that's what a whipping house-elf was for.
Regulus could never mask his flinches every time Mother lashed Kreacher, scolding Sirius for his transgressions, while the sinner smirked, unrepentant. What did an "it" like Kreacher matter to Sirius? Sirius wore his immunity, a badge of unabashed pride, blind to the plight of those who bore the consequences of his mischief.
"Young Master Sirius is a bad boy," Kreacher grumbled quietly to Regulus. "Young Master Sirius breaks my Mistress's heart with his lawless ways. Oh how she cries."
Tears streamed down Regulus's face as he tenderly held Kreacher's hand, watching house magic seam together the wounds on Kreacher's back. Kreacher pat the back of Regulus's hand, not understanding what exactly Kreacher was consoling his little master from but knowing that the gesture had soothed Kreacher's pain when the little master did so. Regulus messily wiped his eyes and nose with a handkerchief, swearing that he would never allow Sirius to lead him astray. For any path that led to Kreacher's pain must be wrong.
On the night Sirius left for Hogwarts, Mother burst into Regulus's bedroom, wand slashing recklessly in mad fury, cutting ribbons into the walls and bed trimmings. Each stroke was a statement punctuated by a banshee wail. Regulus dove toward the wardrobe, dragging Kreacher in with him. Huddled in the back corner, Regulus shielded Kreacher with his small, thin body, while Kreacher covered his little master's ears with worn, scarred hands. But the wardrobe doors and house-elf hands could not keep out Mother's anguish cries. Raw emotion poured out like accidental magic, shattering Regulus's peace, fracturing Mother's fragile mind.
As day broke on September 2nd, Kreacher tugged a sleepy Regulus out from his hiding place. All was calm. Until Regulus caught sight of his newly remodeled bedroom. Then, Kreacher was cleaning fresh spew from the floor.
Gone away were Regulus's calming blue and muted grays. Emerald green and shining silver replaced every surface of his bedroom. Every glance at the garish green inspired a new wave of nausea.
In between heaves, Regulus's hands danced desperately from rubbing his face raw to clean away phantom droplets splattering his face to clutching his throat to staunch the flow, sure that Mother had finally decided his head would be the only honor he could bring House Black.
Acid green
It had been years since the color green evoked a visceral physical reaction from him. First year of Hogwarts was like being under a light Cruciatus: the Black Lake casting a constant sickly green hue over everything in the Slytherin Common Room; his robes trimmed in the damnable color; a matching noose of a House tie wrapped snugly around his throat; his cohorts draped proudly in it at every moment.
Regulus had to perfect Occluding all green, and most blues and yellows, to repress the emotions that the color provoked in him. There was no avoiding it at Hogwarts. At Grimmauld, Regulus could spend his days in the library, and Kreacher could guide him blind to his bed at night and out the door in the morning. But at Hogwarts, he walked alone in the dormitory, was surrounded by a sea of snakes, and had no refuge outside the Common Room where the Marauders couldn't find him. It was a testament to his Quidditch skills that he was able to play Seeker as well as he did despite the disadvantage of his vision.
When Sirius turned seventeen and refused to return to his heir duties, the last of Mother disappeared. For all her bluster and indignation over the years, she had always held hope for his return. She cooed over Regulus in public to remind Sirius of her care of him before he abandoned them for the Potters'. She threatened him with disinheritance to shock him into obedience. When Sirius didn't return home after Hogwarts, she burned his face from the family tapestry, symbolic of her severance from motherhood. For that's all it was, a symbol on ruined enchanted threads; Father was Head of House, and he would never disown his precious heir when the spare was so lacking, despite the dereliction to duty.
"Recruitment is an honor," Walburga crooned. Both hands clutched Regulus' shoulders tightly, painfully."You will serve House Black through your pledge to the Dark Lord."
Regulus suppressed a shudder as he caught sight of the house-elves mounted in the hallway just outside the room from his peripheral. He swallowed a lump that seemed caught by an invisible line on his throat, eyes widening imperceptibly with new understanding: Walburga needed a whipping boy.
It was him or the house-elf she seemed to say, because no one touched Sirius. Not even now. And Regulus wouldn't let anyone touch Kreacher. Not his mother. Not even the Dark Lord.
So Regulus bared his left arm, grit through the pain, and drowned his conscience in his fear.
"Avada Kedavra," intoned Regulus. For the first time in over five years, Regulus saw color again. Bile threatened to choke him as the acid green light left his wand and hit its mark, a muggle man. He dared not flinch or look away while standing before Walburga and the Dark Lord. Still unsure which of them frightened him more.
The Dark Mark undulated grotesquely under his skin. Black on a Black's pale arm. At least, it wasn't green. Thank Merlin for small blessings.
Chartreuse green
Regulus sneered at the emerald potion. The Dark Lord had a flair for the dramatics as evinced by the collage of newspaper cutting on Regulus's bedroom wall. Regulus was sure this was another sick homage to Slytherin.
Occlumency was no longer effective for muting colors for Regulus since that awful summer after Fifth Year. Now, Regulus could smell the thrice-be-damned color. A spectrum of revolting odors to accompany his no longer grey- and sepia- toned vision: stale sweat soaked in fear; hot urine in a crowded room; sulphur wet with fresh blood; freshly waxed floors exposed to stomach acid. Now, he could add sweet rot of bloated corpses to the catalogue.
The cave walls rippled beatifically like stained glass from the glow of the lake surrounding the small island. An eldritch altar for immorality stood at its center with the relic of the Dark Lord's godhood openly displayed as if inviting pilgrims to pay their respects.
It had taken weeks to nurse Kreacher to health in secret after the Dark Lord "borrowed" Kreacher. If Regulus had known that the purpose of his pledge to the Dark Lord was to secure use of a house-elf, then Regulus would have never bothered in the first place. Walburga be damned. It had taken several more weeks to build up his evidence board to figure out the true nature of the request, digging through the old news articles and tracing the Dark Lord's journey back to his school days. Then, a few more weeks to develop this, admittedly Gryffindor-brained, plan. Perhaps Father had the right of it, naming him after the heart of the lion.
Kreacher stood beside Regulus, wringing his hands, anxiously. Kreacher did not fear what this potion would do to him again. Regulus would never harm him, but some kind of harm was promised by the gleam in Regulus's eyes and Kreacher wished against all hope that the harm would be his to take again. But Regulus had not moved since arriving, petrified by what he saw before him, and Kreacher was beginning to despair for any sense of direction. When Regulus finally spoke, Kreacher wished Regulus would have never opened his mouth as each word broke something deep in Kreacher.
"Kreacher, this is an order to be obeyed without exception," Regulus enforced his intent with eye contact. "You will feed me this potion until it is gone, no other commands can supersede this one. After the basin is emptied, you will replace the locket at the bottom with the one in my hand. With the locket you removed from the basin, you will go back to Grimmauld and never return to this cave. You will do whatever you can to destroy that locket. You will not risk your life or wellbeing for mine. You will never speak of this to anyone in House Black. In these commands, you will obey. So mote it be. Do you understand Kreacher?"
Kreacher wailed, unable to deny Regulus's command enhanced with house magic, nodding in response to the question as his body acted without his consent to carry out the orders.
A cruel sense of irony cut the fog of pain. For once, nothing looked more inviting than the pale chartreuse glow of the lake. Thirst. Thirst to end the pain. Thirst for comfort.
Regulus opened his arms welcoming the pull, the grasping limbs pulling him in. The moment his face hit the surface, the mental anguish became an illusion of a nightmare long ago. Body atop a lake of blood became bloodless bodies beneath a lake. Air unbiddening escaped his lungs in a silent scream, replaced by freezing cold water. Sharp bony fingers pierced Regulus, poking him down to the bone, rendering open his flesh. Turbulent rivulets swirled off his open wounds winding olive green paths to the surface as he was dragged further into the depths.
Vision fading black, Regulus was more certain than ever that he loathed all shades of green.