feat(words): parametric color marks — foreground + background pickers (COLOR-3)

Marks now support parametric values via colon syntax:
- color:#hex    — foreground text color
- bgcolor:#hex  — highlight / background color

Existing boolean marks (bold/italic/underline/strike/code) are
unchanged. Empty value (color:, bgcolor:) clears that slot.

Engine
- WordsMark union extended with `color:\${string}` and
  `bgcolor:\${string}` template literal variants.
- isWordsMark accepts the parametric form (validates against #hex
  3/4/6/8 digits).
- normalizeMarks de-duplicates by prefix for parametric marks (only
  one color, one bgcolor per inline survives).
- toggleMarkSet REPLACES same-prefix entries instead of toggling
  them; empty value strips the slot.
- New helpers markValue() and markPrefix() for reading parametric
  data.

Serializers
- HTML out: wrapMarks collects color/bgcolor into a single
  `<span style="color:..;background-color:..">` instead of nested
  spans, then wraps with the boolean-mark tags.
- HTML in: not extended this pass — round-trip via style attr is a
  follow-up. The marks survive in the document model + render OK.
- Markdown out: silently drops parametric marks (no MD syntax for
  inline color; HTML round-trip is the supported path).

DOM render
- createWordsTextAttrs splits marks into booleans (→
  data-words-marks) and parametrics (→ inline `style` attr) so the
  contenteditable paints the colors directly.

Drawer Format panel
- New "Foreground" + "Background" sections with:
  - 10-swatch palette (red/orange/amber/green/cyan/blue/violet/pink/
    white/grey) — hand-picked editorial set
  - Native <input type=color> for free hex pick (no preset constraint)
  - "×" clear button (only when a value is set for that slot)
  - Active swatch outline when the current value matches the preset
- runCommand passes the `color:#hex` / `bgcolor:#hex` string straight
  through commandFromName → toggleMark.

WordsCommandName extended with `color:\${string}` and
`bgcolor:\${string}` for type-safe consumer calls.

152/152 tests pass. Verified visually: clicking the red swatch on
selected "ActiveUI" text in the demo produces
`<span data-words-marks="bold" style="color:#ef4444">ActiveUI</span>`
in the rendered HTML, text paints red in the editor, the swatch
shows active outline + clear (×) button appears.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/uix/eidos/components/words/words-drawer.svelte

@@ -94,6 +94,32 @@
 		{ id: 'bash', label: 'Bash' },
 		{ id: 'python', label: 'Py' }
 	] as const;
+
+	/** Hand-picked palette — keeps the picker compact while covering
+	 *  most editorial intents. Free hex still available via the input
+	 *  next to the chips. */
+	const COLOR_PRESETS = [
+		'#ef4444', // red
+		'#f97316', // orange
+		'#eab308', // amber
+		'#22c55e', // green
+		'#06b6d4', // cyan
+		'#3b82f6', // blue
+		'#8b5cf6', // violet
+		'#ec4899', // pink
+		'#ffffff', // white
+		'#a1a1aa' // grey
+	] as const;
+
+	/** Read the parametric mark value for a given prefix from the
+	 *  active marks. Returns '' when not set. */
+	function currentParametricMark(
+		marks: readonly string[],
+		prefix: 'color' | 'bgcolor'
+	): string {
+		const found = marks.find((m) => m.startsWith(`${prefix}:`));
+		return found ? found.slice(prefix.length + 1) : '';
+	}
 </script>
 
 <Words.Drawer bind:open {defaultOpen} {disabled} {...rest}>
@@ -268,6 +294,78 @@
 			</button>
 		{/each}
 	</div>
+	<div data-words-drawer-section-subtitle>Foreground</div>
+	<div data-words-drawer-color-picker>
+		{#each COLOR_PRESETS as preset (preset)}
+			<button
+				type="button"
+				data-words-drawer-color-swatch
+				data-active={currentParametricMark(s.activeMarks, 'color') === preset ? '' : undefined}
+				style="background-color:{preset}"
+				title={preset}
+				aria-label={`Set foreground to ${preset}`}
+				onmousedown={(e) => e.preventDefault()}
+				onclick={() => s.runCommand(`color:${preset}` as never)}
+			></button>
+		{/each}
+		<input
+			type="color"
+			data-words-drawer-color-input
+			value={currentParametricMark(s.activeMarks, 'color') || '#000000'}
+			aria-label="Pick custom foreground color"
+			oninput={(e) => {
+				const v = (e.currentTarget as HTMLInputElement).value;
+				s.runCommand(`color:${v}` as never);
+			}}
+		/>
+		{#if currentParametricMark(s.activeMarks, 'color')}
+			<button
+				type="button"
+				data-words-drawer-color-clear
+				title="Clear foreground"
+				aria-label="Clear foreground color"
+				onmousedown={(e) => e.preventDefault()}
+				onclick={() => s.runCommand('color:' as never)}
+			>×</button>
+		{/if}
+	</div>
+
+	<div data-words-drawer-section-subtitle>Background</div>
+	<div data-words-drawer-color-picker>
+		{#each COLOR_PRESETS as preset (preset)}
+			<button
+				type="button"
+				data-words-drawer-color-swatch
+				data-active={currentParametricMark(s.activeMarks, 'bgcolor') === preset ? '' : undefined}
+				style="background-color:{preset}"
+				title={preset}
+				aria-label={`Set background to ${preset}`}
+				onmousedown={(e) => e.preventDefault()}
+				onclick={() => s.runCommand(`bgcolor:${preset}` as never)}
+			></button>
+		{/each}
+		<input
+			type="color"
+			data-words-drawer-color-input
+			value={currentParametricMark(s.activeMarks, 'bgcolor') || '#ffff00'}
+			aria-label="Pick custom background color"
+			oninput={(e) => {
+				const v = (e.currentTarget as HTMLInputElement).value;
+				s.runCommand(`bgcolor:${v}` as never);
+			}}
+		/>
+		{#if currentParametricMark(s.activeMarks, 'bgcolor')}
+			<button
+				type="button"
+				data-words-drawer-color-clear
+				title="Clear background"
+				aria-label="Clear background color"
+				onmousedown={(e) => e.preventDefault()}
+				onclick={() => s.runCommand('bgcolor:' as never)}
+			>×</button>
+		{/if}
+	</div>
+
 	<div data-words-drawer-actions data-flush>
 		<button
 			type="button"

src/uix/eidos/components/words/words.css

@@ -397,6 +397,72 @@
 	margin-block-start: 0.4rem;
 }
 
+/* Color picker — palette of swatches + a native <input type=color> for
+   free-pick + a clear button when a value is set. */
+[data-words-drawer-color-picker] {
+	display: flex;
+	flex-wrap: wrap;
+	align-items: center;
+	gap: 0.25rem;
+}
+
+[data-words-drawer-color-swatch] {
+	inline-size: 1.25rem;
+	block-size: 1.25rem;
+	padding: 0;
+	border: 1px solid color-mix(in srgb, var(--words-toolbar-border) 60%, transparent);
+	border-radius: 999px;
+	cursor: pointer;
+	transition: transform 80ms ease, box-shadow 80ms ease;
+}
+
+[data-words-drawer-color-swatch]:hover {
+	transform: scale(1.15);
+	box-shadow: 0 0 0 2px color-mix(in srgb, var(--_words-accent-solid) 30%, transparent);
+}
+
+[data-words-drawer-color-swatch][data-active] {
+	box-shadow:
+		0 0 0 2px var(--words-bg),
+		0 0 0 4px var(--_words-accent-solid);
+}
+
+[data-words-drawer-color-input] {
+	inline-size: 1.6rem;
+	block-size: 1.4rem;
+	padding: 0;
+	border: 1px dashed color-mix(in srgb, var(--words-toolbar-border) 80%, transparent);
+	border-radius: var(--words-command-radius);
+	background: transparent;
+	cursor: pointer;
+}
+
+[data-words-drawer-color-input]:hover {
+	border-style: solid;
+	border-color: var(--_words-accent-border);
+}
+
+[data-words-drawer-color-clear] {
+	display: inline-flex;
+	align-items: center;
+	justify-content: center;
+	inline-size: 1.25rem;
+	block-size: 1.25rem;
+	padding: 0;
+	border: 1px solid color-mix(in srgb, var(--words-toolbar-border) 60%, transparent);
+	border-radius: 999px;
+	background: transparent;
+	color: var(--words-status-color);
+	font-size: 0.9rem;
+	line-height: 1;
+	cursor: pointer;
+}
+
+[data-words-drawer-color-clear]:hover {
+	border-color: var(--words-threat-text);
+	color: var(--words-threat-text);
+}
+
 [data-words-drawer-section-title] {
 	display: flex;
 	align-items: baseline;

src/uix/soma/components/words/engine/document.ts

@@ -1,6 +1,24 @@
 export const WORDS_DOCUMENT_VERSION = 1;
 
-export type WordsMark = 'bold' | 'italic' | 'underline' | 'strike' | 'code';
+/**
+ * Inline mark — boolean format flags ('bold', 'italic', ...) plus
+ * parametric marks carrying a value via colon-prefixed syntax:
+ *   - `color:#ff0000`     foreground text color (hex with #)
+ *   - `bgcolor:#ffeeaa`   highlight / background color
+ *
+ * Parametric marks REPLACE same-prefix entries when toggled (you
+ * can have at most one of each prefix per inline). The HTML
+ * serializer emits them as `style="color:..; background-color:..."`.
+ * Boolean marks toggle as before.
+ */
+export type WordsMark =
+	| 'bold'
+	| 'italic'
+	| 'underline'
+	| 'strike'
+	| 'code'
+	| `color:${string}`
+	| `bgcolor:${string}`;
 export type WordsBlockType =
 	| 'paragraph'
 	| 'heading'
@@ -242,8 +260,30 @@ export function createLink(
 
 export function normalizeMarks(marks: readonly WordsMark[] | undefined): readonly WordsMark[] {
 	if (!marks?.length) return [];
-	const order = new Map<WordsMark, number>(WORDS_MARKS.map((mark, index) => [mark, index]));
-	return Array.from(new Set(marks)).sort((a, b) => (order.get(a) ?? 0) - (order.get(b) ?? 0));
+	const order = new Map<string, number>(
+		(WORDS_MARKS as readonly string[]).map((mark, index) => [mark, index])
+	);
+	// Dedupe boolean marks; for parametric marks (color:X, bgcolor:Y)
+	// keep only the LAST value per prefix so multiple toggles in a
+	// row resolve to the user's final choice.
+	const seenPrefix = new Map<string, WordsMark>();
+	const booleanSet = new Set<WordsMark>();
+	for (const mark of marks) {
+		const colon = mark.indexOf(':');
+		if (colon > 0) {
+			seenPrefix.set(mark.slice(0, colon), mark);
+		} else {
+			booleanSet.add(mark);
+		}
+	}
+	const dedup = [...booleanSet, ...seenPrefix.values()];
+	// Sort: boolean marks first in declaration order, parametric marks
+	// after (stable). This keeps existing tests happy.
+	return dedup.sort((a, b) => {
+		const ai = order.get(a) ?? 1e6;
+		const bi = order.get(b) ?? 1e6;
+		return ai - bi;
+	});
 }
 
 export function sameMarks(
@@ -257,7 +297,30 @@ export function sameMarks(
 }
 
 export function isWordsMark(value: unknown): value is WordsMark {
-	return typeof value === 'string' && (WORDS_MARKS as readonly string[]).includes(value);
+	if (typeof value !== 'string') return false;
+	if ((WORDS_MARKS as readonly string[]).includes(value)) return true;
+	// Parametric: `color:#hex` or `bgcolor:#hex`. Liberal hex check —
+	// anything that's `#` + 3/4/6/8 hex digits.
+	const colorMatch = value.match(/^(color|bgcolor):(#[0-9a-fA-F]{3,8})$/);
+	return !!colorMatch;
+}
+
+/**
+ * Read the parametric value carried by a mark, or undefined for
+ * boolean marks. Returns the part after the colon.
+ *
+ *   markValue('color:#ff0000')   // '#ff0000'
+ *   markValue('bold')            // undefined
+ */
+export function markValue(mark: WordsMark): string | undefined {
+	const colon = mark.indexOf(':');
+	return colon > 0 ? mark.slice(colon + 1) : undefined;
+}
+
+/** Prefix of a parametric mark, or the mark itself for boolean ones. */
+export function markPrefix(mark: WordsMark): string {
+	const colon = mark.indexOf(':');
+	return colon > 0 ? mark.slice(0, colon) : mark;
 }
 
 export function isWordsHeadingLevel(value: unknown): value is WordsHeadingLevel {

src/uix/soma/components/words/engine/dom.ts

@@ -62,10 +62,33 @@ export function createWordsTextAttrs(
 	marks: readonly WordsMark[] | undefined,
 	text: string
 ): WordsDomTextAttrs {
+	// Marks may contain parametric entries (`color:#hex`, `bgcolor:#hex`)
+	// — those translate to an inline `style` attr so the rendered span
+	// paints the color directly. Boolean marks stay in `data-words-marks`
+	// so the existing eidos CSS selectors still apply.
+	const booleans: string[] = [];
+	const styles: string[] = [];
+	if (marks) {
+		for (const mark of marks) {
+			const colon = mark.indexOf(':');
+			if (colon > 0) {
+				const prefix = mark.slice(0, colon);
+				const val = mark.slice(colon + 1);
+				if (prefix === 'color' && /^#[0-9a-fA-F]{3,8}$/.test(val)) {
+					styles.push(`color:${val}`);
+				} else if (prefix === 'bgcolor' && /^#[0-9a-fA-F]{3,8}$/.test(val)) {
+					styles.push(`background-color:${val}`);
+				}
+			} else {
+				booleans.push(mark);
+			}
+		}
+	}
 	return {
 		[WORDS_NODE_ATTR]: 'text',
 		[WORDS_PATH_ATTR]: encodeWordsPath(path),
-		...(marks?.length ? { [WORDS_MARKS_ATTR]: marks.join(' ') } : {}),
+		...(booleans.length ? { [WORDS_MARKS_ATTR]: booleans.join(' ') } : {}),
+		...(styles.length ? { style: styles.join(';') } : {}),
 		...(text.length === 0 ? { [WORDS_EMPTY_TEXT_ATTR]: '' } : {})
 	};
 }

src/uix/soma/components/words/engine/operations.ts

@@ -2665,6 +2665,15 @@ function inlineChildrenText(inlines: readonly WordsInline[]): string {
 }
 
 function toggleMarkSet(marks: readonly WordsMark[], mark: WordsMark): readonly WordsMark[] {
+	const colon = mark.indexOf(':');
+	if (colon > 0) {
+		// Parametric mark — REPLACE any existing entry with the same
+		// prefix. Empty value (`color:`) clears the parametric mark.
+		const prefix = mark.slice(0, colon + 1);
+		const filtered = marks.filter((m) => !m.startsWith(prefix));
+		if (mark.length === colon + 1) return normalizeMarks(filtered);
+		return normalizeMarks([...filtered, mark]);
+	}
 	return normalizeMarks(marks.includes(mark) ? marks.filter((m) => m !== mark) : [...marks, mark]);
 }
 

src/uix/soma/components/words/engine/serialize-html.ts

@@ -25,13 +25,15 @@ import {
 } from '../extensions/table/serialize-html';
 import { createImage, isWordsImageAlign } from '../extensions/image';
 
+/** Boolean-mark to HTML tag map. Parametric marks (color/bgcolor) are
+ *  serialized separately via a <span style=...>; not in this table. */
 const MARK_TAGS = {
 	bold: 'strong',
 	italic: 'em',
 	underline: 'u',
 	strike: 's',
 	code: 'code'
-} as const satisfies Record<WordsMark, string>;
+} as const;
 
 type HtmlNode = HtmlElementNode | HtmlTextNode;
 
@@ -181,10 +183,27 @@ function serializeInlineHtml(inline: WordsInline): string {
 }
 
 function wrapMarks(value: string, marks: readonly WordsMark[]): string {
-	return marks.reduce((html, mark) => {
-		const tag = MARK_TAGS[mark];
+	// Parametric marks (color, bgcolor) get collapsed into ONE span with
+	// a style attr so we don't nest <span> per color slot.
+	const stylePieces: string[] = [];
+	const wrapped = marks.reduce((html, mark) => {
+		const colon = mark.indexOf(':');
+		if (colon > 0) {
+			const prefix = mark.slice(0, colon);
+			const val = mark.slice(colon + 1);
+			if (prefix === 'color' && /^#[0-9a-fA-F]{3,8}$/.test(val)) {
+				stylePieces.push(`color:${val}`);
+			} else if (prefix === 'bgcolor' && /^#[0-9a-fA-F]{3,8}$/.test(val)) {
+				stylePieces.push(`background-color:${val}`);
+			}
+			return html;
+		}
+		const tag = MARK_TAGS[mark as keyof typeof MARK_TAGS];
+		if (!tag) return html;
 		return `<${tag}>${html}</${tag}>`;
 	}, value);
+	if (stylePieces.length === 0) return wrapped;
+	return `<span style="${escapeHtmlAttr(stylePieces.join(';'))}">${wrapped}</span>`;
 }
 
 function escapeHtml(value: string): string {

src/uix/soma/components/words/engine/serialize-markdown.ts

@@ -231,7 +231,11 @@ function serializeInlineMarkdown(inline: WordsInline): string {
 
 function wrapMarkdownMarks(value: string, marks: readonly WordsMark[]): string {
 	return normalizeMarks(marks).reduce((text, mark) => {
-		const [open, close] = MARK_DELIMITERS[mark];
+		// Parametric marks (color, bgcolor) have no markdown equivalent —
+		// drop them on export. They round-trip via HTML instead.
+		const delim = (MARK_DELIMITERS as Record<string, readonly [string, string]>)[mark];
+		if (!delim) return text;
+		const [open, close] = delim;
 		return `${open}${text}${close}`;
 	}, value);
 }

src/uix/soma/components/words/types.ts

@@ -90,7 +90,11 @@ export type WordsCommandName =
 	| 'clear-document'
 	| 'find-text'
 	| 'replace-all-text'
-	| 'commit';
+	| 'commit'
+	/** Parametric color marks — pass through commandFromName to the
+	 *  engine's toggleMark op. Empty value (`color:`) clears. */
+	| `color:${string}`
+	| `bgcolor:${string}`;
 
 export type WordsProviderSnippetProps = {
 	readonly document: WordsDocument;

src/uix/soma/components/words/words-provider.svelte.ts

@@ -1623,6 +1623,13 @@ export class WordsProvider {
 	}
 
 	private commandFromName(name: WordsCommandName, level?: 1 | 2 | 3): WordsCommand | undefined {
+		// Parametric color marks come through as `color:#hex` /
+		// `bgcolor:#hex` (or with empty value to clear). Pass them
+		// directly to the toggleMark op — the engine's toggleMarkSet
+		// REPLACES same-prefix marks instead of toggling them.
+		if (name.startsWith('color:') || name.startsWith('bgcolor:')) {
+			return { type: 'toggleMark', mark: name as WordsMark };
+		}
 		switch (name) {
 			case 'bold':
 			case 'italic':