Enhanced color space support

[SlicedSilver]

Type of PR: enhancement

PR checklist:

• Addresses an existing issue: fixes Support OKLCH color space #1475
• Includes tests
• Documentation update

Note

• I'll squash the commits when merging (since I accidentally duplicated some commits)
• The graphics e2e test runner will be fixed in a separate PR.

Overview of change:

• Built-in sRGB-based colors (rgb, rgba, hex, named color, hsl) are now supported by the library without specific converters, or maps. Instead the rgb equivalent color string is determined by the browser by using window.getComputedStyle(element).color. For most charts, this will only be used for a few colours (like 2 or 3) and the performance effect is insignificant. However this does allow the bundle size to be decreased since we don't need to ship our own parsing converters.
• Custom color parsers can be provided to handle other color (non-sRGB) formats (like p3).
• Added an option to enable p3 expanded color gamut on the canvas (colorSpace)
• It is now possible to use any natively support CSS color format with the library (including expanded colors like display-p3), a custom color parser should be included in the chart options for these additional color formats so that the library can correctly generate contrast colors, and alpha colors as needed (using standard sRGB).

New options:

	/**
	 * Specifies the color space of the rendering context for the internal
	 * canvas elements.
	 *
	 * Note: this option should only be specified during the chart creation
	 * and not changed at a later stage by using `applyOptions`.
	 *
	 * @defaultValue `srgb`
	 *
	 * See [HTMLCanvasElement: getContext() method - Web APIs | MDN](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/getContext#colorspace) for more info
	 */
	colorSpace: ColorSpace;

	/**
	 * Array of custom color parser functions to handle color formats outside of standard sRGB values.
	 * Each parser function takes a string input and should return either:
	 * - An {@link Rgba} array [r,g,b,a] for valid colors (with values 0-255 for rgb and 0-1 for a)
	 * - null if the parser cannot handle that color string, allowing the next parser to attempt it
	 *
	 * Parsers are tried in order until one returns a non-null result. This allows chaining multiple
	 * parsers to handle different color space formats.
	 *
	 * Note: this option should only be specified during the chart creation
	 * and not changed at a later stage by using `applyOptions`.
	 *
	 * The library already supports these color formats by default:
	 * - Hex colors (#RGB, #RGBA, #RRGGBB, #RRGGBBAA)
	 * - RGB/RGBA functions (rgb(), rgba())
	 * - HSL/HSLA functions (hsl(), hsla())
	 * - HWB function (hwb())
	 * - Named colors (red, blue, etc.)
	 * - 'transparent' keyword
	 *
	 * Custom parsers are only needed for other color spaces like:
	 * - Display P3: color(display-p3 r g b)
	 * - CIE Lab: lab(l a b)
	 * - LCH: lch(l c h)
	 * - Oklab: oklab(l a b)
	 * - Oklch: oklch(l c h)
	 * - ...
	 */
	colorParsers: CustomColorParser[];

[github-actions]

size-limit report 📦

Path	Size
ESM	42.32 KB (-2.55% 🔽)
ESM createChart	39.25 KB (-2.66% 🔽)
ESM createChartEx	38 KB (-2.67% 🔽)
ESM Standalone	43.85 KB (-2.29% 🔽)
Standalone	43.79 KB (-2.29% 🔽)
Plugin: Text Watermark	1.86 KB (-0.42% 🔽)
Plugin: Image Watermark	1.69 KB (-0.75% 🔽)
Plugin: Series Markers	3.9 KB (+0.16% 🔺)