You don't find out whether a pair of knickers is any good from trying them on in a changing room with your coat still on. You find out three weeks later, on a day when you've forgotten you're wearing them, which is precisely the point. The ones worth keeping disappear. The ones that aren't announce themselves somewhere around hour six with a waistband that's rolled, dug in, or gone slack in exactly the wrong place.
A proper cotton gusset earns its keep on an ordinary Tuesday more than it ever will on a special occasion, and honestly the special occasion ones are where I'd spend least, because lace and narrow seams are built for a few hours under a dress, not a full day at a desk or a long walk. Winter is when you notice fabric weight most, a slightly heavier cotton blend sits better under thick tights than anything thin and slippery that migrates the moment you sit down. Summer flips the problem, you want something that breathes, because synthetic lace against skin in heat is a special kind of misery I've learned the hard way, on a train with no air conditioning, wondering why I'd ever thought a satin high leg was a sensible choice for July. Where they genuinely fall short is under anything very fitted and pale, a seam or a lace edge will show through no matter how good the knickers are, and no amount of loyalty to a favourite style fixes that.
For colour, I'd steer you towards nude that actually matches your own skin rather than a generic beige, black that's properly black and not the grey a cheap dye fades to after a few washes, and a soft heather or berry if you want something that isn't white but still won't show. White is lovely in theory and a liability in practice, it goes translucent and grubby looking faster than any other shade, which nobody tells you in the shop.
What they clash with isn't really a colour question, it's a fabric one. Anything with a firm structured seam or a thick decorative waistband will fight a slip dress or anything cut close through the hip, you'll see every ridge. Keep the plain, low profile pairs for the clingy things and save the prettier, more structured ones for days when your outfit has some give in it.
Get the plain pair right and that one slim dress you already own, the one you've half blamed for showing every seam, suddenly behaves itself.