Hey sarah im not an expert and i havent tried this kind of tone yet but it's sad to see no one helped u here so i have made some research and the tone of your piano is definitely getting there adding some eq and compression will make it way better oli also uses a space echo and record his piano through a Nagra IV-S and dont forget that olafur's playing is kinda different he always tries to play quietly yet so expressive so maybe practice more and update me :) im gonna buy some mics soon nd im aiming for that tone too any way good luck !!

Welcome rafeek. !

My thoughts are only coming from a mixing engineers point of view so I'm not the best opinion. To my ears, the microphone(s) sound very close which isn't recording the musical tones and ambiance we all really wanting to reproduce. The mics sound way too close to me.

good reference what the OP is shooting for

Yeah true but thats kinda the main purpose of this kind of recording the closed mics are necessary to get that warmth and soft tone but yeah the OP recording’s definitely need more ambiance so putting the third mic a bit further away helps for more dynamic also here’s another example audiokid

And here’s a post of his microphones setup  

This is a very interesting approach /technique. Such beautiful tone, mellow and dreamy.
I suspect a well treated room is a key in achieving the ultimate results. Low frequency room acoustic trapping with something like a Royer SF-24 might be choice.

Coles 4038's and a Rode NT 5 are in no way an equivalent to a pair of KM 84's and a U47. in short it won't sound the same. if you want to make a recording that is similar you will need a pair of pencil condensers and a multi pattern LDC. ribbons are velocity mics ... they work differently than pressure mics like the KM 84. big difference in behavior.

I can’t disagree but a Royer SF 24 is beautiful for adding Uber sweet room and/or overhead ambience that may sound absolutely beautiful in this type of dark recording.
I was thinking (as I owned one) can be used to help brighten up a dark sound (you still want to sound dark but clear and full). But again, that’s if you can control the room reflections.

wish I still had mine

i was responding to the OP. i agree on the Royer though.

btw what's a good alternative for the km84 ? all i could find is the km 184 but they sound brighter than the km84

I have to confess to now using the spitfire una corda quite often, but my own single experiment about ten years ago on a UK aged(badly) Beckstein did exactly what people are experiencing here. The damn sustain pedal noise really was awful - far worse than these examples. My piano tuning friend blamed it on the compressed felt in the mechanism being too hard and the actual mechanism having wear an slack so when the spring pressure was released - the pivot wear let the whole assemble 'relax' - I think that was what he called it.The wear in every joint getting the tension of and sort of stretching? He tried new felt in the actual pedal box but it hardly made a difference. The Spitfire samples have the noise actually recorded as a feature and there is a fader to reduce it, but even fully off - you can still hear the thumps. Maybe it's just a characteristic of any prepared piano?

EDIT
I spotified Olafur Arnalds, expecting more and I won't be listening more - far, far too weird for me.The second track 'woven song' would be a good one for people to ask about on here - if we were presented with it for discussion we'd certainly have mic technique and balance questions. Clearly a style of music I've never experienced before. Not bad, but just odd! the piano and strings are actually quite nice - but the voice is, er, unusual.