Great thread, Carter! I found myself nodding along with many others. Laura's comments that she changes her colours to meet the seasonal light really resonated with me.
My core colour AND core neutral is blue. This make sense, because I've been categorized as a "true or cool summer." Denim blue (s), navy blue, ink blue, French blue, faded chambray blue are for all seasons -- but I can go brighter (cobalt) or lighter (baby blue) in summer and ONLY in summer.
My other neutrals are grey (from charcoal to cool dove grey); taupe (from dark to light); some black (especially in summer, when I can handle that intensity better); white (esp. winter white), and ivory. Can do cream on the bottom if I like.
My colours are cranberry red, all the berries, from cranberry to fuchsia, orchid to plum, teals, and some pinks, plus a bit of blush. An occasional green.
I don't wear orange, yellow or gold, tan, beige, yellowish greens or browns, or corals or peaches. Nothing with a hint of warmth.
(But like Kate, I decorate in the opposite of my personal colours -- our home includes a lot of yellow and gold and sagey to olivey greens and warm reds as well as intense blues and a hit of orange! I love those colours and get to indulge my love in my environment!)
In summer, I tend to lighten and brighten up (with our light) -- and also intensify. So cobalt and black and true white become favourites (in the winter they are too strong for me).
In fall and winter I turn to my softer neutrals -- denim blues, bright navy, taupe. I love teal, orchid, and all the berry tones then. I also wear more grey in winter.
As others have said, I find it freeing and helpful to focus on a specific palette. It's pretty much what I like best on me and it just makes it easier to shop.
I love Vix's idea of looking for items that work specifically together -- this has been an issue for me as proportions change. Very clever strategy -- thanks, Vix!