Cooler grey paint on the walls. A whiter lightbulb and change up the counter top of the vanity.

Easiest first - try cooler light bulbs.

grays and whites will make a small bathroom with no natural light look even dingier and dirtier since you need natural light for a white or off white to read true. The best thing you can do is paint the bathroom a bold color that contrasts.

Here's my bathroom in my old condo with tile in a similar color to yours in my shower. There is no window or natural light in this bathroom. Note how the room looks bright and warm versus dingy and drab? (In the mirror you can see the shower tile.)

I don't have it all figured out- LOL. I just noticed the bathroom referenced in the article has a window and the op's doesn't. Natural light can make a big difference.

First change the lighting to LED bulbs in a bout a 4000K range then choose wall color I would not pain the vanity a color but you could add color with accessories , towels etc.That lighting will give the feel and look of natural daylight.

Well..if I was looking at the bathrooms I'd take cpartits's one. Any day.

(it's not available 'cause some other folks bought it long time ago, I know))

the blog post-the pics look nice with all the styling and all, yet imo they picked a wrong countertop. very wrong. why this marble next to travertine? these two stones don't want to be together. Pretty cool-ish white with bold gray veins next to yellowish tan stone with small veins and shades and whatever else it has. Looks very unnatural to me, this combination.

They shot the after shot with light of thousand suns or how does this quote go..so one can see less the veining on countertop, and travertine seems more white too. I don't think it reflects how stones really look together.

(oh Lil I seeyou commented on that while I was writing my essay lol..yes, exactly. Light)

I think: don't fight the stone..stones usually win:) If you bring very dissimilar stones together-they'll both..win lol. The room will loose though.

So. Simplest countertop..no bold patterns(if in budget to change it at all). Some warm white, cream, light tan maybe.

One minimizes the color he doesn't like often by repetition..as strange as it sounds.

I also have one hall bathroom with tile that mimicks travertine..I don't like it not because it's "dirty", I prefer muddier colors, but because the tile doesn't fit the house's character. I picked the lightest color of the tile, took it to walls..bought the best and longest shower curtain I could find.. similar color but shade I like more, and interesting texture..put a real rug on the floor-they withstand moisture really well, and being small, they're affordable..put there art (real art I owned already), some funny ceramics..no, it's not the best room in my house, it's still a compromise of sorts, but I'm not bothered by that tile as much when I hardly see it anymore.

You can do bolder color too of couse..but I'd mind the stone and wouldn't go against it. I'd pick a warm shade of whatever color you prefer. If red-then brick red. If green then warmer darker green. Deep warm shades. If white-as creamy as possible. (pretty much what you have now, right? Maybe you can go lighter..)

If gray-then so warm a gray it's rather greige or taupe already.

You can create a flow as they say with your other rooms with accents..mine are hidden in the rug, in the art, etc, Small things-yet they will make everything look cohesive even if the bathroom differs a tad more from the rest than you'd prefer.

Ah. And if you have a space for a plant-they always make everything fresh and alive whatever the color palette..such is their nature. Our bathroom is small so I put a ceramic thing-y on the wall and keep there succulents or whatever I have at the moment.

Unfortunately I don't know how to lighten the tile on the floor..I highly suspect that SlipDoctor product that folks use for making tiles less slippery, will take some color away(in my experince it does)..but I'm not sure that's the way to tackle things. Hopefully somebody comes who knows in depth about tiles and stones.

You can change your other faucet and hardware for chrome (or nickel..in short the one you have in bathtub area)..you can go with different mirror to echo things more..I can't see your other rooms, maybe your mirror is perfect for what you want ..but if not, that's another way to tie things. Finish on metal is a color too..in a way..

It will be a very nice bathroom..I'd say: don't fight it completely, make compromises with it.