I only have a few bags(around 12) but I use only a few for my weekdays, to work. It's usually a multifunctional(!) bigger tote or satchel like (but with some structure) for work, as I carry a lot of things and need enough place (but I have a separate bag-a tech black and grey- for my notebook).
From fall to spring I usually consider my bag for my outerwear only (level of formality, color, size, texture and comfort-say are the handles long enough for holding it on my shoulder when I have my coats on?).
My winter coats, and one dressier trench are mainly longer and black -so I usually have one darker and dressier bag to match them (now it's a black patent, and quilted structured satchel with handles AND cross/shoulder strap-but have had some greys, and cognac-too depends on the shoe choices I ever had) and one more casual to contrast them (usually a yellow tote). I find these 2 colors to go/contrast well also with my other 2 shorter trenches/coats wich are a golden brown trench coated with a subtle darker dust(for fall) and a white pleather coat for spring.
Then I have another 2 for work in spring and summer. Usually a slouchy neutral (I generally preffer a very light grey or cream to whites) and one more structured in a color (per moment it's still my 4 yrs old faded coral one). These also go great with my blue denim jacket, or other neutral jackets I have (usually, navy, black, white, grey). Oh, but my summer neutral bag and my yellow fallish one both goes well with a purple cotton jacket, too-which I love.
Then there are some smaller(usually cross body) bags and more casual totes for weekends for all seasons around(usually black, grey, brown or metallic bronze) and beachy holidays (including one bigger shoulder strapped straw bag in yellow again-WHICH I LOVE).
And there are also some clutches, both formals(black sequined) and more casual ones in plain leather(beige, grey and orange) for various functions.
One thing I remarked for myself I love me some hardware(esp if blackened) and that I am more a yellow/mint green/bronze bag girl than a red one/true blue or cobalt/silver or gold one. So I guess it has to do with your personal coloring and/or wardrobe, too.