What would you do with this threshold?

[Winning]

This is the threshold between our hallway and downstairs loo. It's just a random piece of wood as normal thresholds couldn't cope with the height difference between the carpet and tile. At the moment it's just stained a bit with the black grout. Should we paint it white or will it look strange? Or black, something else? Thanks!

I would paint it Matt black, so it looks like an extension of the tiles.

Is the height difference such that you can't have a proper tile-to-carpet doorplate put down, to match the others you have?

Yes, exactly that wowfudge - the height difference due to tile and underfloor heating shenanigans means that we couldn't find a metal tread thingie to fit. So the plumber cut a piece of wood and suggested we paint it but my first idea of white to match the doors etc had me worried it would look odd.

What is the height difference? I can't believe you can find one to fit. We had one that sits at an angle so works for bigger height gaps.

nationalstairnosings.co.uk
Profiles here for different height floors

If you can't find a proper doorplate to fit, then I would paint the wood to match the tiles and use matt varnish over the paint so it stands up to being trodden on.

The internet is great for these kinds of things - often the tradespeople who do the jobs will tell you they can't get what you need/what you need is not available because their usual supplier doesn't stock it, so you can end up with a bit of a bodge. We've had a similar experience over some skirting board.