Continue refactoring

src/utils/string_utils.rs

@@ -92,4 +92,18 @@ pub fn check_youtube_id(id: &str) -> bool {
 pub fn check_emoji_code(shortcut: &str) -> bool {
     let r = Regex::new(r"^:[a-zA-Z0-9]+:$").unwrap();
     r.is_match(shortcut)
+}
+
+/// Check the validity of an HTML color
+///
+/// ```
+/// use comunic_server::utils::string_utils::check_emoji_code;
+///
+/// assert_eq!(check_emoji_code("AAFF00"), true);
+/// assert_eq!(check_emoji_code("ABC"), false);
+/// assert_eq!(check_emoji_code("UUFF00"), false);
+/// ```
+pub fn check_html_color(color: &str) -> bool {
+    let r = Regex::new(r"^:[A-F0-9]{6}:$").unwrap();
+    r.is_match(color)
 }