Brown boots do a different job to black ones, whatever the shop assistant tells you when you're stood there with two pairs and no clue. They soften everything, jeans, cords, a plain dress, and they read as a bit more considered than black without trying hard. The job is simple: something to wear from October to March that isn't trainers and isn't making a statement, just getting you through the day looking like you dressed on purpose.
They're not right for everything, mind. A sharp black trouser suit wants black shoes, not tan ones poking out underneath looking like an afterthought, and anything quite formal or evening leaning will usually sit better in black too. Brown is a daytime colour at heart. On the shade itself, I'd steer towards a mid tan or a chestnut over anything too orange or too pale, because the paler biscuit tones scuff and mark within weeks and show every splash from a puddle, while a proper rich brown hides a multitude. A cheap pair in a flat, matte brown looks like cardboard by February. A good pair, proper leather, a bit of sheen or a natural grain to it, actually looks better after a winter of wear, because the creases and the slight fading start to look like character rather than damage. That's the real difference between the two price points, not how they look new but how they look in month four. Leather ones need a wipe down when they're wet, a decent cream or polish every few weeks, and they'll last years. The cheap synthetic version doesn't improve, it just slowly perishes, cracking across the toe where your foot bends, and no amount of polish fixes that because there's nothing underneath to feed. Before you buy, check the sole is stitched or properly bonded rather than glued on a seam you can see peeling already in the shop, check the zip or lacing sits flat without gaping, and check the heel height against what you'll actually wear them with, because a boot that's perfect under jeans can be a different height problem under a midi skirt or a dress.
Even a good pair won't cope with proper standing water for long, a leather sole and a soaked pavement are not friends, and no brown boot, however well made, is going to do the job of a proper winter boot in genuinely filthy weather. For that you want something rubber soled and frankly less good looking. Brown boots are for getting through an ordinary cold, damp day looking put together, not for wading through anything serious.