Maybe tell us what the color of your trim is and what company you are buying shades from.

I don't know whether you're getting sheer or opaque shades, but if there's any degree of sheerness, the light shining through will make them look different too. That's probably not helpful since you're already having difficulty choosing. :-) When several less than perfect options exist, look at only two at a time. Throw out the one that is the least best of the two. Then put the remaining one up against another. Throw out the one that is the least best and keep doing that until you get down to one left. Consider that you may be the only one who will ever notice a slight difference between your shades and your trim. I didn't have a lot of trouble choosing mine. What is your trim color? If it is really problematic, maybe your trim should be painted. I hate to suggest that because it can be a really big job, but if it is a yellowish color that was popular 20 years ago and doesn't work with anything anymore maybe it's time.

Opaque shades look darker than the front fabric looks by itself.

As kandrewspa indicates, throw out the worst matches first. The best two will likely be indistinguishable from each other. Scrunch up (collapse the cells) the best two samples and pick the one with the edge's color overtones closest to the trim paint color. Sometimes people have different color responses in each eye, so use both eyes. The shades will most likely be drawn at night, so that's a good time to look at the samples with all the lights on.

Very helpful ideas, thank you!

My trim is Sherwin Williams Pure White 7005. Our trim throughout our main floor, and our kitchen cabinets, was painted this color just three years ago so it won't be repainted while we live in the house! :)

I'm willing to buy from any company, though a quote we got from Hunter Douglas was a bit out of our budget, so any company cheaper than that. I've looked at samples from Graber, Bali, Smith and Noble, and a couple of local representatives who carry several lines with names I did not recognize.

The elimination process is a good idea, although different shades are better matches in different lights. Though as apple_pie_order points out, the shades will mostly be down at night so that's what I need to focus on. I think the tip about scrunching up the shades to compare will be helpful.

kandrewspa, yes, I realize most likely I will be the only one who notices any color difference!

Yet another challenging point - some of the shades need to be room darkening (bedroom and TV room.) In my experience looking at samples, the room darkening backing really changes the look of the shade. The silver backing seems to have a worse effect than a white backing.

Thank you to all who have responded so far! And I welcome any more tips.

anj_p, I think one of the reps showed us ALTA, good recommendation, thank you.

Just hunted around and all the pictures of white cellular shades look slightly different than the white trim

To me, it looks just fine. But if it is really going to bother you, then why not get a different color?

Debbi, we need window coverings for our entire main floor and upstairs and if I don't do it all the same, it will never happen. And I think the differences between different whites will be less noticable than trying to match a specific paint color. (For example, both the colored shades you found don't look quite right with their respective wall colors, to me.) And for whatever reason, I'm not a big fan of colored cellular shades, at least not in my house, I realize they can look great in some interiors. Thank you for finding those examples, they are helpful for visualization. I'm going to search Houzz photos now for some white shades with white trim.

I always get the standard Hunter Douglas Daisy White. It looks fine with most of the popular white trim colors. I have used it with BM Simply White, BM Chantilly Lace and a couple of other BM whites I no longer remember!

A comment on mounting hardware: take a close look at the sample shade in the store. Try removing it and reinstalling it. If you can remove and reinstall the shade easily to change the cord that raises and lowers the shade, that's a good shade. If the mounting brackets are a total pain, then get a different shade. Hiring a professional installer every three to five years just to change the worn or broken cord (because you don't have the finger strength to manage the brackets) is an annoying expense.

chispa, I have a sample of Daisy White and it does seem to be a good color but they are pretty expensive. Good to know it is a versatile color, though.

apple_pie_order, thank you, good information to have, I will pass that on to my in house installer (husband.)

Our Alta shades pop on and off very easily. We just pulled them down for a basement remodel and they were a piece of cake.