Changed opacity edit to color edit

lib/pangea/widgets/chat/overlay_message.dart

@@ -46,9 +46,9 @@ class OverlayMessage extends StatelessWidget {
       return const SizedBox.shrink();
     }
 
-    var color = Theme.of(context).colorScheme.surfaceVariant.withAlpha(
-          Theme.of(context).brightness == Brightness.light ? 90 : 160,
-        );
+    var color = Theme.of(context).colorScheme.surfaceVariant;
+    final isLight = Theme.of(context).brightness == Brightness.light;
+    var lightness = isLight ? .05 : .85;
     final textColor = ownMessage
         ? Theme.of(context).colorScheme.onPrimary
         : Theme.of(context).colorScheme.onBackground;
@@ -99,10 +99,22 @@ class OverlayMessage extends StatelessWidget {
     }.contains(event.messageType);
 
     if (ownMessage) {
-      color = Theme.of(context).colorScheme.primary.withAlpha(
-            Theme.of(context).brightness == Brightness.light ? 30 : 160,
-          );
+      color = Theme.of(context).colorScheme.primary;
+      lightness = isLight ? .15 : .85;
     }
+    // Make overlay a little darker/lighter than the message
+    color = Color.fromARGB(
+      color.alpha,
+      isLight
+          ? (color.red + lightness * (255 - color.red)).round()
+          : (color.red * lightness).round(),
+      isLight
+          ? (color.green + lightness * (255 - color.green)).round()
+          : (color.green * lightness).round(),
+      isLight
+          ? (color.blue + lightness * (255 - color.blue)).round()
+          : (color.blue * lightness).round(),
+    );
 
     // #Pangea
     final pangeaMessageEvent = PangeaMessageEvent(