# Styling and themes

> Fills, strokes, fidelity, and keeping a diagram legible in both light and dark.

## Fills and strokes

Shapes take a fill and a stroke from a named palette rather than arbitrary hex.
Palette colours are theme-aware, so a diagram drawn in light mode stays legible
in dark mode.

> [!IMPORTANT]
> A hand-picked hex fill will not adapt. Use the palette on any diagram that
> will ever be read in dark mode. Anything on a public page will be.

## Make colour mean something

Use each hue for exactly one category, consistently. Give data stores one
colour, external systems another, and the subject of the diagram a third. A
rainbow of shapes where colour means nothing is harder to read than no colour
at all.

## Fidelity

Fidelity controls how hand-drawn the rendering looks, from a clean technical
line to a sketchier stroke. It is a per-shape property with a document default.

Sketchy reads as "draft, still moving". Clean reads as "this is the answer".
Keep one fidelity per diagram.

## Theme

<kbd>Shift</kbd> <kbd>Cmd</kbd> <kbd>D</kbd> toggles the editor between light
and dark. Check your diagram in both before publishing, to catch a fill that
only works in one.