Beiges are sneaky.

Part of your problem is that color is not an absolute, it is relative to the other colors in the room. If something in the room is strongly greenish-beige, most beiges will look yellower or pinker than it does.

It is also dependent on the light that hits it.

1 - Try different light bulbs, with a cooler spectrum.

2 - Make sure the undertones of the beige are either grey or purple.

Have you looked at SW 6107 Nomadic Desert? I would call it a caramel beige.

Some beiges seem too fleshy and some seem too green depending on the lighting.

Sabrina Soto used beige a lot on Designed to Sell. Her blog has some useful info on picking beige, along with her favorite beiges. Sabrina's beige picks are all Benjamin Moore colors, but IMO, the splurge for another $10-15/gallon is worth it if it means finding the perfect color; at least they offer sample pots and pints so you don't discover the color is wrong after buying two gallons and spending all day painting! Even bringing tons of paint chips home isn't fool proof, since they're likely just ink-on-paper representations of the color and will reflect light differently than actual paint.

I feel your pain, though; I bought about a dozen sample pots and quarts before picking an off-white/pale-beige for my living room and kitchen. I spent more on samples than I did on the actual gallons of paint, actually, but less than I would have if I'd had to paint the room twice.

Here is a link that might be useful: Sabrina Soto - Beige Beige Beige

Back to buying samples again. I found a Laura Ashley Taupe (Taupe 3 to be exact) and it is very similar to what I had on my walls before but a shade or two lighter which is what I wanted. Bought a sample and tested it out on my walls..so confused again! I painted 4 walls with a color I thought I loved before I stopped after realizing I hated it. It is a light beige which turned out to really be a very light pink. On my remaining one wall is the dark beige.

When I paint over the dark beige with the light beige, the paint color I'm sampling looks perfect, like it should look. When I paint over the lighter pink walls the sample paint is grey and green and gross. Why is it doing this? I painted a white piece of cardboard and held it up to the yucky walls to see if it was the lighting. It looks perfect on the cardboard and icky on the walls. So so confused :-(

Any enlightenment?

Could be that you are not getting complete coverage and the pink base color is still coming through the top coat. Did you apply two full coats to be sure this is not the case? Also, as mentioned, beiges are tricky as they have a tendency to shift - sometimes dramatically - based on lighting. Since you painted a white board and it looks just like the one wall that came out right, it sounds like a coverage issue.