<html xmlns="http://www.w3.org/1999/xhtml"><head></head><body><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="1" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[1]</anchor-end> <anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">CSS</anchor> の<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">色キーワード</anchor> <dfn><code class="CSS">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code></dfn> は、<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">透明</anchor>を表します。
<code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code> は <code class="CSS" xml:lang="en"><anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">rgba</anchor>(0, 0, 0, 0)</code> (<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">透明</anchor>な<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">黒</anchor>)
と等価です。この色はしばしば<dfn><rubyb xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">透明黒<rt xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">transparent block</rt></rubyb></dfn>と呼ばれます。</p><section><h1>仕様書</h1><refs xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:"><ul xmlns="http://www.w3.org/1999/xhtml"><li><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[2]</anchor-end> <strong><cite xml:lang="en">CSS Color Module Level 3</cite> (<time>2011-06-07 21:54:38 +09:00</time> 版) <anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="http://www.w3.org/TR/2011/REC-css3-color-20110607/#transparent">http://www.w3.org/TR/2011/REC-css3-color-20110607/#transparent</anchor-external></strong></li><li><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="10" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[10]</anchor-end> <cite xml:lang="en-US-x-hixie">HTML Standard</cite> (<time>2014-05-05 21:57:42 +09:00</time> 版) <anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="http://www.whatwg.org/specs/web-apps/current-work/#terminology">http://www.whatwg.org/specs/web-apps/current-work/#terminology</anchor-external></li></ul></refs></section><section><h1>意味</h1><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="4" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[4]</anchor-end> <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code> は、完全な<rubyb xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:"><anchor>透明</anchor><rt xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">transparent</rt></rubyb>を表します <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src>。</p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="11" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[11]</anchor-end> <dfn><rubyb xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:"><anchor>透明黒</anchor><rt xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">transparent black</rt></rubyb></dfn>は、<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">赤</anchor>、<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">緑</anchor>、<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">青</anchor>、<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">アルファチャンネル</anchor>がいずれも
0 の<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">色</anchor>を表します <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="10" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;10</anchor-internal></src>。</p></section><section><h1>算出値</h1><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="3" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[3]</anchor-end> <CIDE xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:" class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</CIDE> の<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">算出値</anchor>は <code class="CSS"><anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">rgba</anchor>(0,0,0,0)</code> です <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src>。</p></section><section><h1>歴史</h1><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="5" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[5]</anchor-end> <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code> は <anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">CSS1</anchor> で <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">background-color</anchor>'</code>
<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">特性</anchor>の値として追加されました。 <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="6" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[6]</anchor-end> <anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">CSS2</anchor> で <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">border-color</anchor>'</code> にも <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code>
が認められるようになりました。 <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="7" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[7]</anchor-end> <anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">OEB 1.0.1</anchor> で <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">color</anchor>'</code> にも <code class="CSS" xml:lang="en">'<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">transparent</anchor>'</code>
が使えるようになりました。 <src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="8" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[8]</anchor-end> <anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">CSS3</anchor> で <code class="CSS" xml:lang="en"><anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&lt;color&gt;</anchor></code> が使える場所すべてで使えるようになりました。
<src xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:10:"><anchor-internal xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="2" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">&gt;&gt;2</anchor-internal></src></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="9" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[9]</anchor-end> <cite xml:lang="en">Web Applications 1.0 r5970 </cite>
( (<time>2011-03-30 07:11:00 +09:00</time> 版))
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="http://html5.org/tools/web-apps-tracker?from=5969&amp;to=5970">http://html5.org/tools/web-apps-tracker?from=5969&amp;to=5970</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="12" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[12]</anchor-end> <cite xml:lang="en">Web Applications 1.0 r8754     Try to define what happens when you have tracks that don't cover the whole media timeline</cite>
( (<time>2014-09-09 06:47:00 +09:00</time> 版))
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="http://html5.org/r/8754">http://html5.org/r/8754</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="13" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[13]</anchor-end> <cite xml:lang="en">Editorial: cross-reference transparent black</cite>
(<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">annevk</anchor>著, <time>2017-09-21 22:57:52 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/whatwg/html/commit/7df2378079444ddfb0f4095a3bb78bc382b7c62d">https://github.com/whatwg/html/commit/7df2378079444ddfb0f4095a3bb78bc382b7c62d</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="14" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[14]</anchor-end> <cite xml:lang="en">Editorial: cross-reference transparent black by annevk · Pull Request #3058 · whatwg/html</cite>
(<time>2017-09-24 11:59:17 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/whatwg/html/pull/3058">https://github.com/whatwg/html/pull/3058</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="15" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[15]</anchor-end> <cite xml:lang="en">Make shared worker creation deterministic</cite>
(<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">jakearchibald</anchor>著, <time>2017-09-21 22:27:09 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/whatwg/html/commit/9fda90f44c7c9223de6e3755a043f67ea7c92bf5">https://github.com/whatwg/html/commit/9fda90f44c7c9223de6e3755a043f67ea7c92bf5</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="16" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[16]</anchor-end> <cite xml:lang="en">At @annevk's request, add &amp; export definitions for 'opaque black' and…</cite>
(<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">@annevk</anchor>著, <time>2018-01-17 06:38:39 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/w3c/csswg-drafts/commit/6421e5734c9564fe50b93a92504af08017758521">https://github.com/w3c/csswg-drafts/commit/6421e5734c9564fe50b93a92504af08017758521</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="17" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[17]</anchor-end> <cite xml:lang="en">Use opaque and transparent black as defined in CSS Color</cite>
(<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">annevk</anchor>著, <time>2018-01-18 18:47:53 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/whatwg/html/commit/c26b1562136957680412b5d2bb6ad546d6c8c71a">https://github.com/whatwg/html/commit/c26b1562136957680412b5d2bb6ad546d6c8c71a</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="18" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[18]</anchor-end> <cite xml:lang="en">Define opaque black and reference it by annevk · Pull Request #3366 · whatwg/html</cite>
(<time>2018-01-19 13:28:35 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/whatwg/html/pull/3366">https://github.com/whatwg/html/pull/3366</anchor-external></p><p><anchor-end xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:anchor="19" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:">[19]</anchor-end> <cite xml:lang="en">Use the 'transparent black' and 'opaque black' terms.</cite>
(<anchor xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:">tabatkins</anchor>著, <time>2018-01-20 09:27:27 +09:00</time>)
<anchor-external xmlns="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resScheme="URI" xmlns:a0="urn:x-suika-fam-cx:markup:suikawiki:0:9:" a0:resParameter="https://github.com/w3c/csswg-drafts/commit/c7264a31cd25246342865da685a7e4f514a3ce70">https://github.com/w3c/csswg-drafts/commit/c7264a31cd25246342865da685a7e4f514a3ce70</anchor-external></p></section></body></html>