#brown link

I dunno about Polynesian-coded, but BotW’s Lurelin Village - which bears a striking resemblance to Outset Island - is a village comprised entirely of brown people!  The good news is that The Wind Waker Randomizer already has a built-in feature that lets you customize not only the character model you’re using, but also individual colors on those models:

Can I make it brown?

The answer is yes.  Yes, I absolutely can.

As of now I’ve only touched up the textures on Link’s Ordonian garb, and I imagine this would need to be done for all of his outfits--though that should hardly be difficult.  I don’t know that there are enough people out there who both a) are still playing Twilight Princess in 2019 and b) would use such a thing in the first place to warrant creating a completed pack for general use, but I’ve enough of a vested interest in it that I plan on finishing it regardless.

You’re right, in that it is possible in-universe; almost every Link is a different Link, and the only thing they all have in common beyond a shadow of a doubt is the Spirit of the Hero.  But to actually answer your question - there isn’t a brown Link because Nintendo would never make him brown.

This is a series whose heroes are white and blonde - where the hook-nosed villain is the only prominent man of color across all of the games combined.  Tetra’s skin grows pale when she transforms into Zelda - her “true” self. Although some official art has depicted Marin with darker skin, one look at the Link’s Awakening remake or even Hyrule Warriors dashes all of those hopes away.  And the Gerudo, a race comprised entirely of brown women (aside from Ganondorf) exist inside a bubble of the ultimate male fantasy.

I could say much more, but I wouldn’t be saying anything that hasn’t already been said in much better words by someone more suited than me to say them.  TL;DR: Nintendo treats brown people like dirt, and as such I find it hard to believe that they would ever make the hero of one of their star franchises brown.  You’re right - it is possible - and it should happen - but I won’t be holding my breath on that one.