I'm not a big fan of red, but if you love that color, go for it. I don't know where you live, but Sherwin Williams will help you pick out colors if you buy (I believe) a $75 gift card. They will send a color specialist to your house. What I did was pay for an interior designer to come in and advise. She was $125 an hour, and I just needed an hour with her. She did great picking out colors and giving me advice on the rest of the house, so maybe look into that.

Ok, so in order of the pics, we're looking at flooring, acrylic tub surround and marble (granite?) top? Are these all bought? Did you take a picture of these three elements in the same lighting? I ask because lighting is everything in how we perceive colour and on my monitor (which might not render the colours true), these elements aren't cohesive. The surround looks like a cool grey on my screen while the other two skew warm. All three have a pattern as well which usually makes a small space look busy. That said, you have two horizontal applications (counter and floor) and one vertical (surround) so that will affect how we perceive the colours as well. Will you have a glass shower door or a curtain? If a glass shower door, I'd be tempted to find a colour that relates to the surround (I'd pick the lightest of the swirls). If you'll have a curtain and won't see the surround, I'd pick the lightest colour in your countertop. Bringing a sample to the paint store and having them match your element is one easy way to find that colour. (Both Sherwin-Williams and Benjamin Moore have phone apps that can help you identify their closest match colour to a hard surface.) A greige colour is a chameleon colour that skews both warm and cool grey depending on the light and I'd be tempted to look at those. Benjamin Moore's Silver Satin might be a good one to try. Hope this helps.

There's a Glidden color called Grey Squirrel 30YY 14/070. You can get a chip/sample from The Home Depot or any Pittsburgh Paints Store - they both have Glidden's Master Palette colors. Gauntlet looks VERY battleship gray (no warmth), Gauntlet Gray has a value of 5, that's about right. Hue is 1.42Y-so it should be a warm gray--tending towards brown? GG has an LRV of 17. And it doesn't have a lot of Chroma (colorfulness) so it quite literally is a near neutral gray. Meaning its proportion of grayness is greater than its proportion of colorfulness. Which is why you're perceiving it as battleship gray, no warmth. In comparison, Grey Squirrel has about the same LRV, 14, but it has more than twice the Chroma. Which means it's farther from a true neutral gray. It has more colorfulness and it's not going to look like battleship gray.

The stone is not actual stone, it is likely a veneer. But, it is high quality with the look and feel of stone. Urban Puddy is very close to your inspiration photo. The trim would be done in Elephant Ear. Do you think those colors are simple enough? I am definitely looking for a more classic look.