I opened a can, someone said "it looks kind of pinkish or purpleish."

What you're seeing is the masstone of Agreeable Gray.

Masstone is the color you see when the quantity of a medium (like paint or ink) is so much, so dense that it blocks light from reflecting off the substrate below and bouncing back up through the color. Masstone reflects light off its surface area.

You sense masstone when the medium is in globs, high concentrations, full strength, undiluted or of a generous thickness. Like a freshly opened can of paint.

Printer's ink is the most relate-able example. Cyan ink has a dark blue masstone and magenta ink has a red masstone.

Our entire mainfloor is agreeable grey and it doesn't read purple at all. Its a warm grey and looks more like a greige.

I sampled agreeable grey on my foyer wall and it looked purple. I went with a different grey

What color of artwork would make the paint look more gray or tan, and less purple, if it looks like that when painted?

You don't know that it will look purplish in that space - yet.

Agreeable Gray belongs to the yellow hue family. Kind of over near the yellow-red hue family. You can see where it plots out on this color wheel.

However, in certain qualities of light it can shift and look purplish. Near neutrals from Agreeable Gray's hue family neighborhood are notorious for shifting purple in unbalanced qualities of light.

Which is why you will find some opinions about Agreeable Gray that insist it "has no undertones" it's just a warm neutral gray.

While others will talk about an edge of purpleness that is noticeable in their space.

Just because the masstone looks pinkish or purpleish doesn't mean it will render that way in the space when applied and dried. So it might be a little early to start looking for strategies to counter purpleness that might not even materialize.

If it does shift and look purple, then you know you need to try near neutral grays from a different hue family neighborhood.