{"id":975,"date":"2026-10-17T03:00:00","date_gmt":"2026-10-16T18:00:00","guid":{"rendered":"https:\/\/quantumsea.net\/?p=975"},"modified":"2026-10-17T01:45:29","modified_gmt":"2026-10-16T16:45:29","slug":"qs-wcag-text-contrast-luminance-20261017","status":"publish","type":"post","link":"https:\/\/quantumsea.net\/?p=975","title":{"rendered":"WCAG\u306e\u6587\u5b57\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u3001\u80cc\u666f\u3068\u306e\u660e\u6697\u5dee\u3092\u6570\u5024\u3067\u78ba\u304b\u3081\u308b"},"content":{"rendered":"<p>\u8584\u3044\u7070\u8272\u306e\u6587\u5b57\u306f\u753b\u9762\u306b\u9759\u304b\u306b\u306a\u3058\u307f\u307e\u3059\u304c\u3001\u80cc\u666f\u3068\u306e\u660e\u6697\u5dee\u304c\u5c0f\u3055\u3044\u3068\u3001\u8aad\u3080\u305f\u3081\u306e\u624b\u639b\u304b\u308a\u3082\u5f31\u304f\u306a\u308a\u307e\u3059\u3002\u3067\u306f\u3001\u3069\u306e\u7a0b\u5ea6\u306e\u5dee\u304c\u3042\u308c\u3070\u3088\u3044\u306e\u3067\u3057\u3087\u3046\u304b\u3002Web\u306e\u30a2\u30af\u30bb\u30b7\u30d3\u30ea\u30c6\u30a3\u6307\u91dd\u3067\u3042\u308bWCAG\u306f\u3001\u6587\u5b57\u3068\u80cc\u666f\u306e\u7d44\u5408\u305b\u3092\u300c\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u6bd4\u300d\u3068\u3044\u3046\u6570\u5024\u3067\u78ba\u304b\u3081\u308b\u65b9\u6cd5\u3092\u5b9a\u3081\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u3053\u3067\u306fW3C\u306eWCAG 2.2\u30012024\u5e7412\u670812\u65e5\u52e7\u544a\u7248\u306e\u9054\u6210\u57fa\u6e961.4.3\u300c\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\uff08\u6700\u4f4e\u9650\uff09\u300d\u3092\u4e2d\u5fc3\u306b\u3001\u6570\u5024\u306e\u6210\u308a\u7acb\u3061\u3068\u914d\u8272\u3092\u898b\u76f4\u3059\u624b\u9806\u3092\u6574\u7406\u3057\u307e\u3059\u3002\u898b\u305f\u76ee\u304c\u3088\u304f\u4f3c\u305f\u4e8c\u3064\u306e\u7070\u8272\u304c\u3001\u57fa\u6e96\u306e\u5883\u754c\u3067\u9055\u3046\u5224\u5b9a\u306b\u306a\u308b\u4f8b\u304b\u3089\u898b\u3066\u3044\u304d\u307e\u3059\u3002<sup>\uff3b1\uff3d<\/sup><\/p>\n<section class=\"influvetor-quick-summary\" aria-label=\"\u7c21\u5358\u306b\u307e\u3068\u3081\u308b\u3068\uff1f\">\n<p><strong>\u7c21\u5358\u306b\u307e\u3068\u3081\u308b\u3068\uff1f<\/strong><\/p>\n<ul>\n<li>WCAG 2.2\u306e\u9054\u6210\u57fa\u6e961.4.3\u3067\u306f\u3001\u901a\u5e38\u306e\u6587\u5b57\u306f4.5:1\u4ee5\u4e0a\u3001\u5927\u304d\u306a\u6587\u5b57\u306f\u6761\u4ef6\u3092\u6e80\u305f\u3059\u5834\u5408\u306b3:1\u4ee5\u4e0a\u306e\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u6bd4\u304c\u5fc5\u8981\u3067\u3059\u3002<\/li>\n<li>\u6bd4\u7387\u306f\u6587\u5b57\u8272\u3068\u80cc\u666f\u8272\u306e\u76f8\u5bfe\u8f1d\u5ea6\u304b\u3089\u8a08\u7b97\u3057\u3001\u57fa\u6e96\u3068\u306e\u6bd4\u8f03\u524d\u306b\u306f\u4e38\u3081\u307e\u305b\u3093\u3002\u540c\u3058\u6587\u5b57\u8272\u3067\u3082\u3001\u80cc\u666f\u3092\u66ff\u3048\u308b\u3068\u7d50\u679c\u304c\u5909\u308f\u308a\u307e\u3059\u3002<\/li>\n<li>\u6bd4\u7387\u3092\u6e80\u305f\u3059\u3053\u3068\u3068\u3001\u5b9f\u969b\u306b\u8aad\u307f\u3084\u3059\u3044\u3053\u3068\u306f\u540c\u3058\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u6587\u5b57\u306e\u5927\u304d\u3055\u30fb\u592a\u3055\u30fb\u8868\u793a\u72b6\u614b\u3082\u4e00\u7dd2\u306b\u78ba\u8a8d\u3057\u307e\u3059\u3002<\/li>\n<\/ul>\n<\/section>\n<h2>4.5:1\u306f\u3001\u6587\u5b57\u3068\u80cc\u666f\u306e\u7d44\u5408\u305b\u306b\u5bfe\u3059\u308b\u57fa\u6e96<\/h2>\n<p>\u9054\u6210\u57fa\u6e961.4.3\u306f\u30ec\u30d9\u30ebAA\u306b\u4f4d\u7f6e\u4ed8\u3051\u3089\u308c\u3001\u539f\u5247\u3068\u3057\u3066\u6587\u5b57\u3068\u6587\u5b57\u753b\u50cf\u306b4.5:1\u4ee5\u4e0a\u3092\u6c42\u3081\u307e\u3059\u3002\u5927\u304d\u306a\u6587\u5b57\u306b\u306f3:1\u4ee5\u4e0a\u3068\u3044\u3046\u6761\u4ef6\u304c\u3042\u308a\u307e\u3059\u3002\u6587\u5b57\u3092\u753b\u50cf\u306b\u3057\u3066\u3082\u3001\u6587\u7ae0\u3068\u3057\u3066\u8aad\u307e\u305b\u308b\u305f\u3081\u306e\u3082\u306e\u306a\u3089\u3001\u3053\u306e\u78ba\u8a8d\u304b\u3089\u5916\u308c\u308b\u308f\u3051\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<sup>\uff3b1\uff3d<\/sup><\/p>\n<p>\u3053\u3053\u3067\u3044\u3046\u6bd4\u7387\u306f\u3001\u300c\u3053\u306e\u7070\u8272\u306a\u3089\u5e38\u306b\u4f7f\u3048\u308b\u300d\u3068\u3044\u3046\u8272\u5358\u4f53\u306e\u8a55\u4fa1\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u767d\u3044\u80cc\u666f\u3067\u5341\u5206\u306a\u5dee\u304c\u3042\u3063\u3066\u3082\u3001\u8584\u3044\u7070\u8272\u306e\u80cc\u666f\u3078\u79fb\u305b\u3070\u5dee\u306f\u7e2e\u307e\u308a\u307e\u3059\u3002\u672c\u6587\u3001\u30ab\u30fc\u30c9\u3001\u5165\u529b\u6b04\u306a\u3069\u3001\u5b9f\u969b\u306b\u63a5\u3059\u308b\u80cc\u666f\u3068\u306e\u7d44\u5408\u305b\u3092\u78ba\u8a8d\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\u540c\u30581.4.3\u306b\u306f\u3001\u64cd\u4f5c\u3067\u304d\u306a\u3044\u72b6\u614b\u306e\u90e8\u54c1\u306b\u542b\u307e\u308c\u308b\u6587\u5b57\u3001\u7d14\u7c8b\u306a\u88c5\u98fe\u3001\u307b\u304b\u306e\u8996\u899a\u60c5\u5831\u3092\u542b\u3080\u5199\u771f\u306b\u5076\u7136\u5199\u3063\u305f\u6587\u5b57\u3001\u30ed\u30b4\u3084\u30d6\u30e9\u30f3\u30c9\u540d\u306e\u4e00\u90e8\u306a\u3069\u306e\u4f8b\u5916\u304c\u3042\u308a\u307e\u3059\u3002\u305f\u3060\u3057\u300c\u30d6\u30e9\u30f3\u30c9\u3067\u6c7a\u3081\u305f\u8272\u3060\u304b\u3089\u300d\u3068\u3044\u3046\u7406\u7531\u3067\u3001\u901a\u5e38\u306e\u8aac\u660e\u6587\u307e\u3067\u4f8b\u5916\u306b\u306a\u308b\u308f\u3051\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u5165\u529b\u6b04\u306e\u30d7\u30ec\u30fc\u30b9\u30db\u30eb\u30c0\u30fc\u3084\u3001\u30db\u30d0\u30fc\u30fb\u30ad\u30fc\u30dc\u30fc\u30c9\u30d5\u30a9\u30fc\u30ab\u30b9\u6642\u306b\u8868\u793a\u3059\u308b\u6587\u5b57\u3082\u5bfe\u8c61\u3067\u3059\u3002<sup>\uff3b1\u30012\uff3d<\/sup><\/p>\n<h2>\u76f8\u5bfe\u8f1d\u5ea6\u306f\u3001RGB\u306e\u6570\u5b57\u3092\u305d\u306e\u307e\u307e\u5e73\u5747\u3057\u306a\u3044<\/h2>\n<p>\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u6bd4\u306e\u8a08\u7b97\u306b\u306f\u3001\u8272\u3092\u660e\u6697\u306e\u91cf\u3078\u7f6e\u304d\u63db\u3048\u308b\u300c\u76f8\u5bfe\u8f1d\u5ea6\u300d\u3092\u4f7f\u3044\u307e\u3059\u3002\u6700\u3082\u6697\u3044\u9ed2\u30920\u3001\u6700\u3082\u660e\u308b\u3044\u767d\u30921\u3068\u3059\u308b\u6bd4\u8f03\u7528\u306e\u5024\u3067\u3059\u3002\u753b\u9762\u304b\u3089\u51fa\u308b\u5149\u3092\u5b9f\u6e2c\u3057\u305f\u5024\u3067\u306f\u306a\u304f\u3001\u3053\u3053\u3067\u6271\u3046\u4f8b\u3067\u306fsRGB\u306e\u8272\u6307\u5b9a\u304b\u3089\u6c42\u3081\u307e\u3059\u3002\u8272\u76f8\u304c\u9055\u3046\u304b\u3069\u3046\u304b\u3088\u308a\u3001\u6587\u5b57\u3068\u80cc\u666f\u306e\u660e\u6697\u5dee\u306b\u7740\u76ee\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002<sup>\uff3b1\u30012\uff3d<\/sup><\/p>\n<p>Web\u3067\u3088\u304f\u4f7f\u3046<code>#777777<\/code>\u306e\u3088\u3046\u306a\u8272\u306f\u3001\u8d64\u30fb\u7dd1\u30fb\u9752\u3092\u305d\u308c\u305e\u308c0\u301c255\u306e8\u30d3\u30c3\u30c8\u5024\u3067\u8868\u3057\u3066\u3044\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u305d\u306e\u5024\u306f\u5149\u306e\u91cf\u306b\u5bfe\u3057\u3066\u76f4\u7dda\u7684\u306b\u5897\u3048\u308b\u5c3a\u5ea6\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u5404\u6210\u5206\u3092\u5149\u306e\u91cf\u306b\u5bfe\u5fdc\u3059\u308b\u5024\u3078\u5909\u63db\u3057\u3066\u304b\u3089\u3001\u91cd\u307f\u3092\u4ed8\u3051\u3066\u5408\u8a08\u3057\u307e\u3059\u3002\u7dd1\u306e\u4fc2\u6570\u306f\u8d64\u3084\u9752\u3088\u308a\u5927\u304d\u304f\u3001\u5358\u7d14\u306aRGB\u306e\u5e73\u5747\u3068\u306f\u7570\u306a\u308a\u307e\u3059\u3002<sup>\uff3b1\uff3d<\/sup><\/p>\n<ol>\n<li><strong>\u5404\u6210\u5206\u30920\u301c1\u3078\u3002<\/strong>\u8d64\u30fb\u7dd1\u30fb\u9752\u305d\u308c\u305e\u308c\u306e8\u30d3\u30c3\u30c8\u5024\u3092255\u3067\u5272\u308a\u3001\u305d\u306e\u5024\u3092<code>c<\/code>\u3068\u3057\u307e\u3059\u3002<\/li>\n<li><strong>\u5149\u306e\u91cf\u306b\u5bfe\u5fdc\u3059\u308b\u5024\u3078\u5909\u63db\u3002<\/strong><code>c \u2264 0.04045<\/code>\u306a\u3089<code>c \/ 12.92<\/code>\u3001\u305d\u308c\u3088\u308a\u5927\u304d\u3051\u308c\u3070<code>((c + 0.055) \/ 1.055)<sup>2.4<\/sup><\/code>\u3068\u3057\u307e\u3059\u3002<\/li>\n<li><strong>\u76f8\u5bfe\u8f1d\u5ea6L\u3092\u8a08\u7b97\u3002<\/strong>\u5909\u63db\u5f8c\u306e\u8d64\u30fb\u7dd1\u30fb\u9752\u3092R\u30fbG\u30fbB\u3068\u3057\u3066\u3001<code>L = 0.2126R + 0.7152G + 0.0722B<\/code>\u3092\u6c42\u3081\u307e\u3059\u3002<\/li>\n<\/ol>\n<p>\u6b21\u306b\u3001\u6587\u5b57\u3068\u80cc\u666f\u306e\u3046\u3061\u660e\u308b\u3044\u65b9\u306e\u76f8\u5bfe\u8f1d\u5ea6\u3092L1\u3001\u6697\u3044\u65b9\u3092L2\u3068\u3057\u3001<strong>\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u6bd4 = (L1 + 0.05) \/ (L2 + 0.05)<\/strong>\u3068\u8a08\u7b97\u3057\u307e\u3059\u3002\u767d\u3068\u9ed2\u306a\u3089<code>(1 + 0.05) \/ (0 + 0.05) = 21<\/code>\u306721:1\u3001\u540c\u3058\u8272\u540c\u58eb\u306a\u30891:1\u3067\u3059\u3002\u6697\u3044\u80cc\u666f\u306b\u660e\u308b\u3044\u6587\u5b57\u3092\u7f6e\u304f\u5834\u5408\u3082\u3001\u660e\u308b\u3044\u65b9\u3092\u5206\u5b50\u3078\u7f6e\u304f\u8a08\u7b97\u306f\u5909\u308f\u308a\u307e\u305b\u3093\u3002<sup>\uff3b1\uff3d<\/sup><\/p>\n<h2>4.48\u3092\u300c4.5\u300d\u3068\u8868\u793a\u3057\u3066\u3082\u3001\u57fa\u6e96\u306f\u6e80\u305f\u3055\u306a\u3044<\/h2>\n<p>\u767d\u80cc\u666f\u306e<code>#777777<\/code>\u3092\u8a08\u7b97\u3057\u3066\u307f\u307e\u3059\u300216\u9032\u6570\u306e77\u306f10\u9032\u6570\u3067119\u306a\u306e\u3067\u3001\u5404\u6210\u5206\u306f<code>119 \/ 255<\/code>\u3001\u7d040.4667\u3067\u3059\u3002\u4e0a\u306e\u5909\u63db\u3092\u884c\u3046\u3068\u76f8\u5bfe\u8f1d\u5ea6\u306f\u7d040.184475\u3002\u767d\u306e\u76f8\u5bfe\u8f1d\u5ea61\u3068\u7d44\u307f\u5408\u308f\u305b\u305f\u6bd4\u7387\u306f\u3001\u7d04<strong>4.478089:1<\/strong>\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u3053\u306e\u5024\u306f\u901a\u5e38\u6587\u5b57\u306e4.5:1\u3092\u308f\u305a\u304b\u306b\u4e0b\u56de\u308a\u307e\u3059\u3002\u8868\u793a\u3092\u5c0f\u65701\u6841\u3078\u4e38\u3081\u308c\u3070\u300c4.5\u300d\u306b\u898b\u3048\u307e\u3059\u304c\u3001\u5408\u683c\u306b\u306f\u3067\u304d\u307e\u305b\u3093\u3002W3C\u306e\u89e3\u8aac\u306f\u30014.499:1\u30824.5:1\u306e\u6761\u4ef6\u3092\u6e80\u305f\u3055\u306a\u3044\u4f8b\u3068\u3057\u3066\u6319\u3052\u3001\u4e38\u3081\u308b\u524d\u306e\u8a08\u7b97\u5024\u3067\u6bd4\u8f03\u3059\u308b\u3088\u3046\u8aac\u660e\u3057\u3066\u3044\u307e\u3059\u3002<sup>\uff3b2\uff3d<\/sup><\/p>\n<p>\u4e00\u65b9\u3001\u5c11\u3057\u6697\u3044<code>#767676<\/code>\u306f\u5404\u6210\u5206\u304c118\u3067\u3001\u767d\u80cc\u666f\u3068\u306e\u6bd4\u7387\u306f\u7d04<strong>4.542225:1<\/strong>\u3067\u3059\u3002\u3053\u3061\u3089\u306f4.5:1\u4ee5\u4e0a\u306b\u306a\u308a\u307e\u3059\u3002\u308f\u305a\u304b\u306a\u8272\u6307\u5b9a\u306e\u5dee\u3067\u3082\u3001\u3057\u304d\u3044\u5024\u306e\u3069\u3061\u3089\u5074\u306b\u3042\u308b\u304b\u306f\u5909\u308f\u308a\u307e\u3059\u3002\u300c\u76ee\u3067\u9055\u3044\u304c\u5206\u304b\u3089\u306a\u3044\u307b\u3069\u8fd1\u3044\u300d\u3053\u3068\u306f\u3001\u540c\u3058\u5224\u5b9a\u306b\u3059\u308b\u7406\u7531\u306b\u306f\u306a\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u4ee5\u4e0b\u306f\u4e0d\u900f\u660e\u306a\u5358\u8272\u306esRGB\u3092\u524d\u63d0\u306b\u8a08\u7b97\u3057\u305f\u4f8b\u3067\u3059\u3002\u8868\u306e\u6bd4\u7387\u306f\u8aad\u307f\u3084\u3059\u3055\u306e\u305f\u3081\u5c0f\u65702\u6841\u306b\u3057\u3066\u3044\u307e\u3059\u304c\u3001\u5224\u5b9a\u306b\u306f\u4e38\u3081\u308b\u524d\u306e\u5024\u3092\u4f7f\u3063\u3066\u3044\u307e\u3059\u3002\u753b\u9762\u3084\u8aad\u8005\u306b\u3088\u308b\u898b\u3048\u65b9\u306e\u5b9f\u6e2c\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<div style=\"overflow-x:auto\">\n<table>\n<caption>\u6587\u5b57\u8272\u3068\u80cc\u666f\u8272\u3092\u5909\u3048\u305f\u5834\u5408\u306e\u8a08\u7b97\u4f8b<\/caption>\n<thead>\n<tr>\n<th scope=\"col\">\u6587\u5b57\u8272<\/th>\n<th scope=\"col\">\u80cc\u666f\u8272<\/th>\n<th scope=\"col\">\u6bd4\u7387<\/th>\n<th scope=\"col\">\u901a\u5e38\u6587\u5b57\u306e4.5:1<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th scope=\"row\"><code>#767676<\/code><\/th>\n<td><code>#FFFFFF<\/code><\/td>\n<td>4.54:1<\/td>\n<td>\u6e80\u305f\u3059<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\"><code>#777777<\/code><\/th>\n<td><code>#FFFFFF<\/code><\/td>\n<td>4.48:1<\/td>\n<td>\u6e80\u305f\u3055\u306a\u3044<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\"><code>#767676<\/code><\/th>\n<td><code>#F0F0F0<\/code><\/td>\n<td>3.99:1<\/td>\n<td>\u6e80\u305f\u3055\u306a\u3044<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\"><code>#666666<\/code><\/th>\n<td><code>#F0F0F0<\/code><\/td>\n<td>5.04:1<\/td>\n<td>\u6e80\u305f\u3059<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>3\u884c\u76ee\u3067\u306f\u6587\u5b57\u8272\u3092\u5909\u3048\u305a\u3001\u80cc\u666f\u3060\u3051\u3092\u767d\u304b\u3089\u8584\u3044\u7070\u8272\u306b\u3057\u3066\u3044\u307e\u3059\u3002\u305d\u308c\u3060\u3051\u3067\u6bd4\u7387\u306f\u7d043.99:1\u3078\u4e0b\u304c\u308a\u307e\u3059\u3002\u305d\u3053\u30674\u884c\u76ee\u306e\u3088\u3046\u306b\u6587\u5b57\u3092\u6697\u304f\u3059\u308b\u3068\u3001\u8584\u3044\u7070\u8272\u306e\u80cc\u666f\u3067\u3082\u7d045.04:1\u3092\u78ba\u4fdd\u3067\u304d\u307e\u3059\u3002\u80cc\u666f\u3092\u6b8b\u3057\u3066\u6587\u5b57\u3092\u5909\u3048\u308b\u306e\u304b\u3001\u6587\u5b57\u3092\u6b8b\u3057\u3066\u80cc\u666f\u3092\u5909\u3048\u308b\u306e\u304b\u3002\u6bd4\u7387\u3092\u898b\u308b\u3068\u3001\u914d\u8272\u306e\u3069\u3061\u3089\u3092\u8abf\u6574\u3059\u308b\u304b\u3092\u5177\u4f53\u7684\u306b\u8003\u3048\u3089\u308c\u307e\u3059\u3002<\/p>\n<figure>\n<a href=\"https:\/\/quantumsea.net\/wp-content\/uploads\/2026\/10\/qs-wcag-text-contrast-luminance-20261017-source-figure-1-6688658844b8.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/quantumsea.net\/wp-content\/uploads\/2026\/10\/qs-wcag-text-contrast-luminance-20261017-source-figure-1-6688658844b8.png\" alt=\"\u540c\u3058\u7070\u8272\u306e\u6587\u5b57\u3067\u3082\u80cc\u666f\u3068\u306e\u7d44\u5408\u305b\u3067\u30b3\u30f3\u30c8\u30e9\u30b9\u30c8\u6bd4\u304c\u5909\u308f\u308b\u6bd4\u8f03\u56f3\u3002\u767d\u80cc\u666f\u306e#767676\u306f4.54\u3001#777777\u306f4.48\u3002\u8584\u3044\u7070\u8272#F0F0F0\u306e\u80cc\u666f\u3067\u306f#767676\u304c3.99\u3068\u306a\u308a\u3001\u6587\u5b57\u3092#666666\u3078\u6697\u304f\u3059\u308b\u30685.04\u306b\u306a\u308b\u3002\u5224\u5b9a\u306f\u4e38\u3081\u308b\u524d\u306e\u5024\u3092\u4f7f\u3046\u3002\" width=\"1200\" height=\"1280\" style=\"max-width:100%;height:auto\" 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href=\"https:\/\/www.w3.org\/TR\/2024\/REC-WCAG22-20241212\/\">W3C, Web Content Accessibility Guidelines (WCAG) 2.2<\/a> \u2014 2024\u5e7412\u670812\u65e5\u52e7\u544a\u3002\u9054\u6210\u57fa\u6e961.4.3\u30015.1\u30015.2.1\u3001\u7528\u8a9e\u5b9a\u7fa9\u300ccontrast ratio\u300d\u300clarge scale\u300d\u300crelative luminance\u300d\u3002\u898f\u7bc4\u672c\u6587\u3068\u60c5\u5831\u63d0\u4f9b\u306e\u6ce8\u8a18\u30fb\u4f8b\u3092\u533a\u5225\u3057\u3066\u53c2\u7167\u3002Copyright \u00a9 2020\u20132024 World Wide Web Consortium.<\/li>\n<li><a href=\"https:\/\/www.w3.org\/WAI\/WCAG22\/Understanding\/contrast-minimum.html\">W3C WAI, Understanding Success Criterion 1.4.3: Contrast (Minimum)<\/a> \u2014 \u898f\u7bc4\u3068\u306f\u5225\u306e\u89e3\u8aac\u8cc7\u6599\u3002\u4fdd\u5b58\u7248\u306e\u66f4\u65b0\u8868\u793a\u306f2026\u5e749\u67086\u65e5\u3002\u975e\u4e38\u3081\u5224\u5b9a\u3001\u6587\u5b57\u30b5\u30a4\u30ba\u3001\u30a2\u30f3\u30c1\u30a8\u30a4\u30ea\u30a2\u30b9\u3001\u4f8b\u5916\u3068\u9069\u7528\u5bfe\u8c61\u3092\u53c2\u7167\u3002Copyright \u00a9 2026 World Wide Web Consortium.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u8584\u3044\u7070\u8272\u306e\u6587\u5b57\u306f\u753b\u9762\u306b\u9759\u304b\u306b\u306a\u3058\u307f\u307e\u3059\u304c\u3001\u80cc\u666f\u3068\u306e\u660e\u6697\u5dee\u304c\u5c0f\u3055\u3044\u3068\u3001\u8aad\u3080\u305f\u3081\u306e\u624b\u639b\u304b\u308a\u3082\u5f31\u304f\u306a\u308a\u307e\u3059\u3002\u3067\u306f\u3001\u3069\u306e\u7a0b\u5ea6\u306e\u5dee\u304c\u3042\u308c\u3070\u3088\u3044\u306e\u3067\u3057\u3087\u3046\u304b\u3002Web\u306e\u30a2\u30af\u30bb\u30b7\u30d3\u30ea\u30c6\u30a3\u6307\u91dd\u3067\u3042\u308bWCAG\u306f\u3001\u6587\u5b57\u3068\u80cc\u666f\u306e\u7d44\u5408\u305b\u3092\u300c\u30b3\u30f3\u30c8 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