I would prime and paint the ceiling and the trim and then choose a soft gray/ green to go with the floors it is impossible to get something that works with all those colors .

Given a yellowish ceiling and a pink-beige floor (and the brown trim) what paint color do I choose without creating a clash between these two colors ?

Orange. Also known as (YR) Yellow-Red in my world.

The pink and yellow don't relate to each other as a pair because the geometry is off. A quick look at a color wheel will show you how to fix any color combination that doesn't look right or looks like it's missing something.

In the case of pink and yellow, something is missing. And that's a bridge color to link the two. In this case it's colors from the orange (YR) hue family.

The geometry of a color wheel applies to all colors, purely saturated, tints, tones, shades, near neutrals - all of 'em are included.

Read this blog post. It might help: https://thelandofcolor.com/how-to-fix-a-bad-beige-color-scheme/

Lori- that makes perfect sense. I never imagined that a bridge was the way to go. I have long been leaning towards SW 7012 Creamy. Do you find this to be an adequate bridge?

BM Muslin does work great with travertine....except I have a yellow wood ceiling.

Here are the whitest orange-based whites I could find (that I could tolerate)

Creamy belongs to the yellow hue family, might not be blush enough.

You need something definitely YR like Biscuit, Intricate Ivory or Choice Cream. Maybe even try Patience to see how it looks with the floor. BTW, brown is usually just dark orange.

If you find a YR neutral for the walls, the Travertine might not look as pinkish. I lived in El Paso for 7 years. Saw - and lived with - my fair share of Travertine and I know its color is easily influenced. I think it's because it's natural stone and the nuance of color is so deeply layered. I dunno but I've seen pink Travertine shift to a mellow yellow more times than I can count.

BenM's Muslin OC-12 is worth checking out too.

Here are the whitest orange-based whites I could find (that I could tolerate)

They will all change in context of the Travertine. Travertine is magical like that. Def don't rule anything out based solely on what you see online.

I painted my kitchen a muted sage green and logic dictates that should have made the miles of "pink" Travertine look more pink. It didn't. Instead it shifted and looked mellowy almond cream.