@@ -225,6 +225,11 @@ Opting Into a Preferred Color Scheme: the 'color-scheme' property {#color-scheme
225225 To ensure particular foreground or background colors,
226226 they need to be specified explicitly.
227227
228+ Note: [[HTML]] specifies a
229+ <a href="https://html.spec.whatwg.org/multipage/semantics.html#meta-color-scheme">color-scheme</a>
230+ <{meta}> tag which can be used to set the color-scheme on the root element as
231+ a [[css-cascade-4#preshint|non-CSS presentational hint]] .
232+
228233 Note: Earlier versions of this property also defined an <css> only</css> keyword
229234 to be specified alongside a preferred color scheme,
230235 indicating a stronger author preference.
@@ -260,47 +265,6 @@ Effects of the Used Color Scheme {#color-scheme-effect}
260265 via elements intended for graphics
261266 (such as <{img}> elements embedding an SVG document).
262267
263- The "color-scheme" <{meta}> value {#color-scheme-meta}
264- ---------------------------------
265-
266- To aid user agents in rendering the page background with the desired [=color scheme=] immediately
267- (rather than waiting for all CSS in the page to load),
268- a 'color-scheme' value can also be provided in a <{meta}> element.
269-
270- If any <{meta}> elements are [=inserted into a document=] or [=removed from a document=] ,
271- or existing <{meta}> elements have their <{meta/name}> or <{meta/content}> attributes changed,
272- user agents must run the following algorithm:
273-
274- <div algorithm="find the color-scheme meta">
275- 1. Let |candidate elements| be the list of all <{meta}> elements that meet the following criteria,
276- in [=tree order=] :
277-
278- * the element is [=in a document tree=]
279- * the element has a <{meta/name}> attribute,
280- whose value is an [=ASCII case-insensitive=] match for <code> color-scheme</code>
281- * the element has a <{meta/content}> attribute,
282- whose value is not the empty string
283- * the element is a child of the [=the head element=] of the document
284-
285- 2. For each |element| in |candidate elements|:
286- 1. If |element|’s <{meta/content}> attribute's value
287- [=CSS/parses=] as a <'color-scheme' > value,
288- treat that value as a declaration of the 'color-scheme' property on |element|’s [=tree/root=] ,
289- cascaded as a [[css-cascade-4#preshint|non-CSS presentational hint]] .
290- Then return.
291-
292- Note: Because these rules check successive elements until they find a match,
293- an author can provide multiple such values
294- to handle fallback for legacy user agents.
295- Opposite how CSS fallback works for properties,
296- the multiple <{meta}> elements must be arranged
297- with the legacy values <em> after</em> the newer values.
298- </div>
299-
300- Issue(#3846): This algorithm favors the first <{meta}> ,
301- to allow for ASAP rendering with a chosen color scheme.
302- Is that the desired behavior?
303-
304268
305269Forced Color Schemes: the 'forced-color-adjust' property {#forced}
306270====================
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