What color should I paint my basement floor?

Battleship Gray.

Steel blue epoxy paint. The color flakes make it more interesting without if feeling like too much and its easy to clean up. Good since basements can get damp.
Epoxy paint.

Depends if you like modern or warm and cozy and how much money you have and how creative you are. You could go white for modern. Beige or brown for cozy. Or a bright color, or a pattern for some fun.

The concrete stains are amazingly beautiful, here are some photos on this site. I like it better than some ceramic tiles.

Personally I like color. Maybe a dark forest green or a brick red or something with some zing to it and that will not show dirt. Get creative!

Everything sounds very neutral, so if you are not planning on reselling anytime soon or are willing to repaint it if you do, I would go with a nice, but not too bright or jarring pop of color.

I agree with @JLeslie that stains are a great option instead of painting. They are stunning and have a more subtle effect than solid paint. They are also more durable than paint, which tends to get damaged when walked on. Here are some stain color samples to give you an idea of your options. I’m personally a fan of the deep, rich colors, like teals/blues, purples, and brown-red tones. And if you wanted to stay more neutral, the dark greys/browns and blacks are also beautiful and would stand out in their own sense.

If you want to stick to lighter neutral tones, I would opt for paint instead, because the light stains come out looking slightly off and unfinished, in my opinion. You can also achieve much lighter hues with paint than are possible with stains, for obvious reasons.

I like the pop of color idea, too. Whatever your accent color is going to be in the room (throw pillows, artwork, vases, etc.) If your accent color is going to be red, for instance, pick a shade of red and stain or paint the hallway floor that color.

If you paint consider using epoxy.

Use a quality paint designed for basements and you can go whatever color you want. My neighbor just painted his concrete basement floor so it looks like Italian Marble.

I like a dark dull earthtone terra cotta sort of like as if it were brick only a little greyer as a nod to the cement. Any darkish, low key color that works with your beige. And when I was picking colors for exhibits that [as they all did] were mounted on a reddish cast “fake tile” floor, I picked a baseboard color that was between the floor color and the wall color.

I agree with using the quality paint. Looks lousy when it is half worn off. My condo bought cheap paint for the concrete laundry room floor and it has worn through, making the room look crummy even though the walls and ceiling look still fresh.