--- /dev/null
+# declaration-colon-space-after
+
+Require a single space or disallow whitespace after the colon of declarations.
+
+```css
+a { color: pink }
+/** ↑
+ * The space after this colon */
+```
+
+## Options
+
+`string`: `"always"|"never"|"always-single-line"`
+
+### `"always"`
+
+There *must always* be a single space after the colon.
+
+The following patterns are considered violations:
+
+```css
+a { color :pink }
+```
+
+```css
+a { color:pink }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color : pink }
+```
+
+```css
+a { color: pink }
+```
+
+### `"never"`
+
+There *must never* be whitespace after the colon.
+
+The following patterns are considered violations:
+
+```css
+a { color:pink }
+```
+
+```css
+a { color :pink }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color :pink }
+```
+
+```css
+a { color:pink }
+```
+
+### `"always-single-line"`
+
+There *must always* be a single space after the colon *if the declaration's value is single-line*.
+
+The following patterns are considered violations:
+
+```css
+a {
+ box-shadow:0 0 0 1px #5b9dd9, 0 0 2px 1px rgba(30, 140, 190, 0.8);
+}
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a {
+ box-shadow: 0 0 0 1px #5b9dd9, 0 0 2px 1px rgba(30, 140, 190, 0.8);
+}
+```
+
+```css
+a {
+ box-shadow:
+ 0 0 0 1px #5b9dd9,
+ 0 0 2px 1px rgba(30, 140, 190, 0.8);
+}
+```
+
+```css
+a {
+ box-shadow:0 0 0 1px #5b9dd9,
+ 0 0 2px 1px rgba(30, 140, 190, 0.8);
+}
+```