I, too will be reading this thread!!
And you can do the samples and figure out what color is best, and what formulation.
I was excited about getting the "free" sample pots of Everyday Minerals for only $3.65 in shipping. It sounds great - in theory - and
if you happen to hit upon some of the right colors the first time out. You do get plenty of product in a little pot.
BUT: if you're like me, don't know what colors/shades to get, you can end up with five sample pots all of the wrong colors.

The first try, all the foundation colors were way too light.

They also sold out of the blush I wanted & substituted a color completely one I wouldn't have picked. So I can't even use it with liquid foundations.
The second try, the foundation colors are all too yellow, even though the medium tones might be a better shade.
NOW: $7 down the hole, I'm reticent to fork over another $3.65 to try again. That's almost $11 in "generously portioned" samples I can't use - except as skin toned eye shadows.

I could have bought one of the cheaper Minerals lines at Rite Aid. With their 100% cosmetic guarantee, I could have returned any/all colors that weren't right & tried again.
I feel like they mineral makeup might be accentuating some of my drier areas...
Anyway, I am toying with the idea of returning to the higher end liquid foundations to see if they help with the aging/dryness issues but I just haven't mustered up the energy to do it!
A friend also commented on how the Everyday Minerals accentuated some of my drier areas, creating lines that weren't noticable before, making me look older than before.
Also, I found I really have to have my face carefully exfoliated nearly every other day, or ANY dry, rough patches are really emphasized. I'm thinking these Mineral powders are really for younger aged skin that don't need as much "work".
Diane Sawyer mentioned that in some interview on aging. That those of us over forty, really have to stay away from powder foundations. I should have listened.

Oh, well, I had to try it.
If nothing else, with all the work it took to keep exfoliated, extra attention to re-moisturize dry patches, and all that buffing & blending of the powders, it has really made me appreciate my liquid foundations.
I take extra time really blending with the sponge now, and try to use a lot less than before - except on the dark sunspots. I think I may just have to get a finer milled translucent powder to set the liquid foundation. So I'll probably stick with the liquids. (I still hate how I can't fall asleep with it on though.

)