1 files changed, 31 insertions, 0 deletions
diff --git a/guidelines/wikipedia/color.js b/guidelines/wikipedia/color.js
new file mode 100644
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+++ b/guidelines/wikipedia/color.js
@@ -0,0 +1,31 @@
+exports.name = "Color use";
+exports.description = "Use colors that have sufficient contrast and avoid issues with common forms of color blindness.";
+
+var fc = fiveui.color;
+var AA_RATIO = 4.5;
+var AAA_RATIO = 7;
+
+exports.rule = function (report) {
+  $5('#mw-content-text *')
+    // filter for lowest level elts having non-empty text
+    .filter(function () {
+      var $this = $(this);
+      return $this.children().length == 0 && $.trim($this.text()).length > 0;
+    })
+    .each(function (i) {
+      var fg = fc.colorToRGB($(this).css('color'));
+      var bg = fc.findBGColor($(this));
+      if (fg && bg) {
+        var ratio = fc.contrast(fc.luminance(fg), fc.luminance(bg));
+
+        if (ratio < AA_RATIO) {
+          report.error('Element has poor contrast: ' + ratio +
+                       " ratio should be greater than " + AA_RATIO, this);
+        } else if (ratio < AAA_RATIO){
+          report.warning('Element has poor contrast: ' + ratio +
+                      " ratio should be greater than " + AAA_RATIO, this);
+        }
+      }
+  });
+
+};