--- /dev/null
+# color-hex-case
+
+Specify lowercase or uppercase for hex colors.
+
+```css
+a { color: #fff }
+/** ↑
+ * These hex colors */
+```
+
+The `--fix` option on the [command line](../../../docs/user-guide/cli.md#autofixing-errors) can automatically fix all of the problems reported by this rule.
+
+## Options
+
+`string`: `"lower"|"upper"`
+
+### `"lower"`
+
+The following patterns are considered violations:
+
+```css
+a { color: #FFF; }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color: #000; }
+```
+
+```css
+a { color: #fff; }
+```
+
+### `"upper"`
+
+The following patterns are considered violations:
+
+```css
+a { color: #fff; }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color: #000; }
+```
+
+```css
+a { color: #FFF; }
+```