Colours for the visitor site's theme. Presets: ready-made light and dark sets. One colour: pick a single brand colour and get all six colours back (primary, page background and card, for light and dark). Every tile is drawn with the rules of the Preview on the admin Site > Theme page.
Pick one of these, mix your own in the palette below, or type a hex. Each card already shows what you would get.
Mix your own
Drag in the palette: to the right is more vivid, up is lighter. The strip below it sets the hue. Arrow keys work too (Shift for bigger steps).
Soft darkDeep dark
Fine-tune the six colours
Edit any of them; the tiles follow.
Readability checksWhat is decided for you, and why
Your colour is the light primary, unchanged.
Dark primary: the same hue and vividness, made lighter only when it is too dark for a dark page (lightness floor 0.68). In 13 real themes the dark accent is at the median only 0.12 lighter than the light one, and four use the same colour in both modes.
Page and card: near white in light mode, near black in dark mode, with a faint tint of your hue. The five tint styles the earlier prototype offered differed by at most 0.025 (barely visible), so they are not a choice. The dark page starts at lightness 0.23, the median of the 13 real themes (their range is 0.15 to 0.33), and the Dark mode depth slider takes it down to 0.16.
One method: hand-written rules in OKLCH, which came closest to the real themes (mean distance 0.041 against 0.067 for Material 3 and 0.064 for Ant Design). The comparison is on the research page.
Nothing picked yet. Press Pick on a card.
Research version with the three methods side by side, a twelve-hue sweep and the check against real themes: research.html. Design issue and data: cheesecave-admin#23.