A/N: Day 2 of the 'Royai Week' prompt challenge! Today's is 'Colour'. Enjoy.

Red was Roy Mustang's favourite colour: it was the colour of fire, heat and passion. He liked it on cars, he liked it on clothing, and he especially liked it on Riza Hawkeye.

This is a fact that Riza worked out years ago and completely by accident.

. . .

It had been a warm summer in East City. The shared office was proving to be a nightmare; the mass collection of men and Riza Hawkeye bundled into one small room in a heatwave being akin to bathing in the fire pits of Hell.

"You're allowed to remove your jackets, men," Mustang had given in, sweat rolling down his back.

"Finally," Havoc was unsurprisingly the first to quip, and within seconds had discarded his thick militarily jacket, revealing the white undershirt of their uniforms.

The rest of the office had followed; Fuery, Breda, Falman and Mustang himself. The only one being stubborn and resolute was Hawkeye.

Riza's hair was limp and her face was rosy and glistening with perspiration. But the colour in her cheeks wasn't just from the heat. It was a mild anxiety and panic. Because beneath her white undershirt, her bra was neon red.

This choice of riskay underwear wasn't a deliberate decision that morning; long office hours had left Riza with very little time for laundry and thus very little choice of appropriate work bras.

"Uh, Lieutenant?" Roy had prompted. "You're pretty irreplaceable to me, I'd rather you didn't die of heatstroke."

"Gee thanks, Colonel," 2nd Lieutenant Havoc piped up again. Mustang shoots him a glare.

"I'm okay," Riza lied stiffly.

The rest of them glanced at her. They knew Hawkeye was tough, but this was taking it too far.

She made it through an hour of agonising heat before she snapped. Swearing colourfully, Riza had all but ripped her military jacket off, throwing it unceremoniously onto the floor and fanning herself openly with the report she'd been working on.

Riza was so hot she'd soaked her white undershirt leaving it almost transparent, displaying her neon red bra to all of her colleagues.

The men had stopped what they were doing and stared. Sometimes, they forgot she was a woman. They all shifted their eyes around the room looking embarrassed but also impressed.

But none of them were as flustered as Roy Mustang who had turned almost as red as Hawkeye's bra.

Havoc threw a paper airplane onto Roy's desk and when he opened it read; you are one lucky bastard.

Mustang resisted the temptation with much difficulty to set Havoc alight.

Riza was back buried in her work, trying to ignore the stir she'd caused amongst the rest of them. She was so hot, she almost didn't care that her entire squad could see her chest and the most provocative item of clothing she owned.

The rest of the day had passed uneventfully and finally the soldiers began to file out until it was just Roy and Riza left.

"You know," Roy began with a suggestive smile. "You really caught me off guard earlier."

Riza covered her face in embarrassment. "I'm so sorry; I've had no time to –"

Roy cut her off with a kiss, as hot and heavy as the day had been. In no time, Riza's shirt was on the floor and she'd been lifted onto the desk by an eager and lustful Roy Mustang who began kissing all over her chest.

"God damn, Lieutenant, why have I never seen this bra before?" Mustang had growled, running his hands over the lace.

"Because it's trashy and loud," Riza half heartedly complained, her legs wrapped around Roy's waist and her hands knotted in his hair.

"I like trashy and loud," Roy had insisted. "And red looks really good on you, Hawkeye."

. . .

Now, the red bra had been joined by a family of lacy red undergarments, and it had become a sort of seductive in-joke between the two of them.

"Are you ready yet?" Roy called through the bathroom door, shaking back his sleeve and checking his watch.

"Almost!"

They were getting ready for a black tie dinner for the military. A relatively unimportant event, but it was much anticipated by Roy who rarely got to see Riza dressed up. He goes and sits on the bed next to Black Hayate. The dog has his head in his paws and looks at Roy quizzically.

"I know," Roy tickles Hayate behind the ears. "She never usually takes this long."

"I can hear you!" Riza yells from the bathroom and Roy makes a face at the dog.

Eventually, the door opens and there stands Riza in a full length, figure hugging red dress, the cleavage of which dips past her sternum.

Roy gulps.

Her hair is swept up more elegantly then her usual clip, and her makeup is done for once, the look being completed with red lipstick.

Roy thanks every deity imaginable for the ability to see her right now.

"My god, Riza …" Roy is speechless.

"Don't worry," Riza walks towards him and lifts up one leg, resting it on the bed next to Roy whose heart beats wildly. She pulls aside the deep slit in her dress to reveal black and silver glittered heels, and a thigh holster with two pistols. "I'm still prepared for any situation."

Roy flounders for words and Riza stands straight with a playful smile on her face. Roy stands too and kisses her hard, encircling his arms around her petite waist.

"What did I ever do to deserve a woman like you?" Roy sighs in open adoration.

"I'd say that you must have done something terrible in a former life, but who am I kidding? I'm a catch." Riza winks. Roy melts.

"You sure are, Lieutenant."

"You've got lipstick on you," Riza uses her thumb to gently rub off the red kiss mark from Roy's lips.

"Good thinking, Hawkeye," Roy can't resist kissing her on the cheek. "Red doesn't look as good on me as it does on you."