For my first 3D capsule wardrobe (I've started thinking about it as a cube), I'm going with a cool winter color scheme that has touches of spring colors. I'm hoping to transition into spring nicely. The main colors are ones that I have quite a bit of in my stash, but the accent ones not as much. I hope to do very little buying for this and what I do will now be focused on this.
My main colors are: royal blue, gray, navy.
My neturals are black and white.
My accent colors are: green, cream, purple and berry pink.
The colors for a capsule wardrobe are selected by filling in three categores: neutrals, main color, accents. Anuschka Rees, author of The Curated Closet (which I haven't read yet, but have requested from the library), has an excellent description of this here, as well as list of example palettes here. For discussions that are more focused on fabrics, you can find more info from the Curvy Sewing Collective, here, or from Colette's Wardrobe Architect series, here.
The next step is to plan projects by pulling fabric and patterns. My favorite part!