Why is the horse blue

Princess Celestia, Diarch of Equestria

A platter of earthy-scented tea slowly floats towards her snout, the cup lifting so she can enjoy its aroma.

Princess Celestia, the once Monarch, now Diarch, Princess of the Sun, was deeply enjoying her breakfast. Truthfully, the food in front of her wasn't the source -- though she was certain her little ponies went above and beyond -- but for this day, it was the liveliest that Princess Luna had been, since her return. She'd barely lost the spring in her step from holding her section of the night, and even as breakfast was rounding out, it seemed she still had mounds of energy to burn, if her echoed and distant shouting was anything to go by.

Princess Celestia wasn't quite sure... what Princess Luna was going on about, but her fervor for the topic brought a smile to the Sun Goddesses once-worried face.

And a frown to her nephews, who buried his face in his hooves.
"Auntie--"
"Yes, Prince Blueblood?"
"Must Aunt Luna--"
"I believe she must, if the urgency in her tone is to be believed."
His eyes trail to the pile of weapons assorted to where her Breakfast used to be. Princess Celestia follow shortly, but it only elects a giggle.
"Auntie, she kept me up all night!"
"Like you don't do that to yourself with that Marefriend of yours?" Celestia tosses a raised eyebrow from behind her cup of tea, sipping softly. Blueblood stiffens, managing a cough.
"I suppose, Auntie... we all have our... nights."
"As we do, Prince Blueblood, as we--"

The dining room doors burst open, presenting Princess Luna, fully dressed in outdated Midnight-Themed battle armor, trailed by a Thestral guard with some hefty bags under his eyes. Several weapons, mostly polearms, are awkwardly strapped to his back, and several more float behind Luna in a semi-circle, grasped tightly by her magics.

"SISTER!" The midnight colored pony shouts, rattling most of the silverware with her voice.

Celestia seems to have forgotten just how deep the royal armory seems to run, but nonetheless smiles when she sees her sister.
"Yes, Luna?"
"WE RIDE FOR BATTLE! IF THOU SHALT NOT SEE US THIS EVENING..."
"I'll see you in the Morning, Luna. Go have your fun." Celestia giggled, waving her sister away with a hoof. Not that Luna needed permission, but Celestia had offered to take a few of her nights duties so Luna could spend more time in this... valiant hunt. Luna apparently had quite the interaction during her dreamwalking, and seeks to conquer a particularly nasty Nightmare. Her dedication to her role was heartwarming.

Of course, Lunas version of events, with some information withheld for her own sake, didn't quite translate the full effect, though neither quite seemed to pick up on that.

Nodding furiously, Luna charges off for her room, to gather her strength for the morrows battle. The Thestral guards legs buckle, and he slumps straight down onto his belly, legs in every direction as weapons clatter off his back.
"...Your service to the crowns is, as always, deeply appreciated, Midnight Light." Celestia says behind a soft smile.
"...Ever eager to serve." The Thestral manages to utter, sighing.

Princess Luna, The Overconfident

Luna barreled into her room, slamming the doors shut. Thick curtains keep her sisters sun out, the room dark mind for a pair or blue-flame candles near her bed.

The variety of glowing weapons she'd been carrying clatters to the floor as she releases them, diving into her bed. Despite her flamboyant declaration of a war March, she had been up all night. First, she would sleep. Then, she would pinpoint that creatures dreams, hunt them down, and eviscerated them for Equestrias sake. None else must be... exposed, and traumatized, to those nubbed claws.

Those... dextrous, lithe, agile...
She shakes her head violently, helmet flying off her head as she dives under the covers. This was her burden, her duty. She would bear the scars from this creature, to spare the rest of pony kind from them.

She had even sent ahead a letter of warning to the Twilight Sparkle, alerting her sisters precious student of the proximity of the creature, though she assured the young student that it would be dealt with.

Now, her trial... to beat these thoughts off amidst her slumber. The Princess surrenders to the longing for sleep, curling up in the dark. She shivers as her thoughts drift, snorting. Then, snoring.

Anondus, enjoyer of Midday Naps

A meager yawn escapes Anondus, as he enjoys his peaceful walk, unaware of how often he skirts danger. He'd stopped calling for Garlik at this point, which was also well timed. Prowling Timberwolves, poison joke--Ignorance is bliss, and in Anondus' case, safety, as if some higher entity guided his path.

Up until he finds another upturned log, laid amidst moss in a small glade.
"Oh, scoreth. A divine spot."

Slumping against the log, his supplies tumble beside himself as Anondus sighs, relaxing against its surprisingly squishy surface. He'd found a particularly crisp river earlier, so his waterskin was refilled, but it didn't solve his 'being lost' problem.

The odd flower and mushroom grew around this little glade, but as Anondus checked, thankfully none of them in a circle. The log was a welcome comfort. It had him start thinking about moss blankets--up until he was snoring.

Princess Luna, the Ambushed

While Luna could dreamwalk during her own sleep, few creatures that lived under the Equestrian banner found the day to be the time to rest. So, she resorted to her own, as she often did.

Even amidst the temptations, the Princess of the Night was in full control of her own dreams. Here, she would plan against the beast, conjuring its shape to best find how to defeat it, on her own terms. Her own arena, her own machinations.

Though... this looks an awful lot like that Nightmare the creature had the other night. No matter, she'll simply think of somewhere else.

Somewhere. Else.

Ah, one of Canterlots local Cafe, the Belated Bellow. A quaint location open late, perfect for the rare morning Luna wanted to get out and treat herself to their Blueberry Tarts. She is alone... the Cafe, empty, the worker, busy, the streets, empty. Not quite what she envisioned, but perhaps she needed more time to relax.

She sighs dreamily, inhaling the sweet aroma of the freshly baked--

Her eyes snap open as an offending scent takes its place. Sat across from her is the creature, with a dumb expression plastered across its stupid face. She tenses, wings flaring out defensively. Remove it, Luna. She squints, focusing -- IT WOULD NOT IMPEDE HER DREAM! SHE WAS STRONGER!

Anondus, the mostly confused

Huh, new dream. Funky. Some kind of city, but the buildings were smaller. Fancy castle, though. Looks like it could withstand a good few months of siege.

When Anondus opened his eyes, he'd been pleasantly surprised to find he wasn't thrust deep in his usual dreams. A little odd, with how quiet it was--but he was even more surprised to find he had company. The Blorse was back, seemingly engrossed in... smelling baked goods on a plate in front of itself.
"...And I thought it was weird the last time." He mumbles--which seems to startle the Blorse, snapping it out of its stupor. It glares at him, snorting loudly before it shuts its eyes, hard enough that Anondus sees a vein start to bulge.

He reaches over the table, one hand helping himself to one of its baked treats, the other scratching the top of its snout.

The table thuds and the plate rattles as the Blorses head drops onto it like a sack of potatoes, a soft purr escaping it. This thing was just putty for pets. Cute.

Tart--the Blueberry kind, apparently, and rather tasty at that--half-hanging out of his mouth, Anondus starts scratching both of its cheeks, the deep blue fur rustling and bristling under the rather careless strokes and scratches. If it could turn into a puddle, the Blorse probably would, with the noises this thing was making. A mix between a purr, a whinny and a growl. Its wings were twitching, and it was leaning against the table, smushing itself against the wooden surface to try and lean further into the affection, radiant eyes glazed and staring into the distance... then they rolled back into its head, alright.... oh, now they're locked onto Anondus. And they stayed there.

For a long time. The rest of the dream... didn't really get any better for the poor Princess. Or, it did. Depends on perspective. Definitely got further, though; Anondus had never seen a horse react like that to a backscratch.

Man, was she soft though.

Twilight Sparkle, Element of Autism

Buried deep in a fort crafted of tomes and books, Twilight Sparkle used her horn to illuminate the pages as her tired eyes slowly scrawled a most fascinating read; 'Mane Kampf'. By A.Colt Hoofler. A Unicorn that informed how one could best ply their Unicorns horned heritage over their fellow Pegasus and Earth ponies... he had some interesting ideas. She'd have to talk to Princess Celestia about--

The doors to her study burst open as Spike practically scrambles in, hoisting up a scroll into the air.
"Spike!" Twilights head bursts out from under a few of the books, her magic lowering them to the ground.
"I told you, no kicking open doors!"

Spike wiggles the scroll in the face, her eyes crossing to try and focus on it.
"Sorry, Twi--but this ones from Luna!"

That sentence alone forgave any prior upset, the purple unicorns eyes widening in excitement. She exchanged letters all the time with Celestia, but Luna?! She practically tore it open, the pair leaning in to gauge its contents. Perhaps, a royal summons... or Celestia was sick, and Luna had to take over! Or, maybe she wanted to take TWILIGHT AS A PUPIL TOO!

...

"...Creature in the Everfree?" She trails off re-reading the last few lines. A little dissapointing, but the curiosity kept her rapt interest.
"Aren't there always creatures in the Everfree? Like, not the ones that live there, but like, the ones that end up being problems?" Spike asks, turning his attention to Twilight, a pang of worry in his voice.

Twilight purses her lips, rolling the scroll back up. The other Elements were indisposed at the moment, dragged away by obligations; she could maybe convince Apple jack... no, she could do this alone. The protection of Ponyville, even without the other Elements, meant she just had to be careful.
"It'll be alright, Spike. Help me pack a saddlebag. I'm going to speak to Zecora, and see if she's seen the creature. If Luna herself is writing about it, then I want to at least be on top of things."

Spike relented, the two taking a moment to tidy up, and prepare a travel bag. Mostly, Spike cleaned up the slowly collapsing bookfort, and Twilight made more of a mess preparing as she dug things out from under piles to shove into her bags, but such was hardly new. The worried muttering didn't do much to help his mood, but, Twilight seemed confident at least.

Locking the Library behind them, with Spike sat on her back, Twilight trots through Ponyville, towards the outskirts of the Everfree.