fix(expo): reject 3-digit hex in theme validation and fix Android 8-digit hex ordering

chriscanin · chriscanin · commit 19bc65a8f51c · 2026-04-10T13:45:23.000-07:00
- Remove 3-digit hex (#RGB) from the prebuild validation regex. Both native
  parsers only handle 6- or 8-digit hex, so 3-digit values would pass validation
  but be silently ignored at runtime.
- Convert RRGGBBAA to AARRGGBB on Android before passing to parseColor. iOS
  already parses 8-digit hex as RRGGBBAA, so without this conversion the same
  color token could render differently on each platform.
diff --git a/packages/expo/android/src/main/java/expo/modules/clerk/ClerkExpoModule.kt b/packages/expo/android/src/main/java/expo/modules/clerk/ClerkExpoModule.kt
@@ -438,7 +438,12 @@ class ClerkExpoModule(reactContext: ReactApplicationContext) :
         return try {
             when (cleaned.length) {
                 6 -> Color(android.graphics.Color.parseColor("#FF$cleaned"))
-                8 -> Color(android.graphics.Color.parseColor("#$cleaned"))
+                // Theme JSON uses RRGGBBAA; Android parseColor expects AARRGGBB
+                8 -> {
+                    val rrggbb = cleaned.substring(0, 6)
+                    val aa = cleaned.substring(6, 8)
+                    Color(android.graphics.Color.parseColor("#$aa$rrggbb"))
+                }
                 else -> null
             }
         } catch (e: Exception) {
diff --git a/packages/expo/app.plugin.js b/packages/expo/app.plugin.js
@@ -618,7 +618,7 @@ const VALID_COLOR_KEYS = [
   'shadow',
 ];
 
-const HEX_COLOR_REGEX = /^#([0-9A-Fa-f]{3}|[0-9A-Fa-f]{6}|[0-9A-Fa-f]{8})$/;
+const HEX_COLOR_REGEX = /^#([0-9A-Fa-f]{6}|[0-9A-Fa-f]{8})$/;
 
 function validateThemeJson(theme) {
   const validateColors = (colors, label) => {
