diff --git a/booking.studygroups.inc b/booking.studygroups.inc
index 615bf91..ebda724 100644
--- a/booking.studygroups.inc
+++ b/booking.studygroups.inc
@@ -519,26 +519,23 @@ function booking_studygroups_edit_form_submit($form, &$form_state) {
 					array(':eid' => $event->eid, ':nid' => $nid));
 	$person_groups = $person_groups_query->fetchAllAssoc('booking_studygroup_id');
 
-	//select all the study groups for this event id
-	$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
-	$studygroups = $studygroups_query->fetchAll();	
+	//select any readings groups so we know if we need to update colours
+	$reading_groups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid AND booking_is_readinggroup = 'Y'", array(':eid' => $event->eid));
+	$reading_groups = $reading_groups_query->fetchAllAssoc('sid');	
 	
 	//loop through array of study group IDs and compare against existing database entries
-	foreach ($studygroup_ids as $key => $value)
-	{
+	foreach ($studygroup_ids as $key => $value) {
 		//watchdog('booking', "<pre>Study Group key:\n@key\nValue\n@value</pre>", array('@key' => print_r( $key, true), '@value' => print_r( $value, true)));
 
 		//check if there is a valid value to process
-		if ($value > 0 || $value == 'Remove')
-		{
+		if ($value > 0 || $value == 'Remove') {
 			//if there was no previous mapping but Remove has been selected anyway, just skip to the next value to look at
 			if (empty($person_groups[$key]) && $value == 'Remove')
 			{
 				continue;
 			}
 			//check to see if we need to remove a study group mapping
-			if (! empty($person_groups[$key]) && $value == 'Remove')
-			{
+			if (! empty($person_groups[$key]) && $value == 'Remove') {
 				watchdog('booking', "Removing an existing Study Group session id: @id from group @group.\n<pre>@info</pre>", 
 					array('@id' => $value, '@group' => $key, '@info' => print_r( $person_groups[$key], true)));
 				
@@ -547,36 +544,32 @@ function booking_studygroups_edit_form_submit($form, &$form_state) {
 				 	->execute();				
 			}
 			//check for an existing study group mapping to change
-			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id != $value)
-			{
+			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id != $value) {
 				watchdog('booking', "Updating Study Group session from: @key to @value for id @id", 
 					array('@key' => $person_groups[$key]->booking_session_id, '@value' => $value, '@id' => $nid));
 
 				db_update('booking_studygroup_mapping')
 				  ->fields(array(
 					'booking_session_id' => $value,
-					//'booking_is_leader' => $person_groups[$key]->booking_is_leader,
-					//'booking_is_helper' => $person_groups[$key]->booking_is_helper,		
-					//'booking_is_reserveleader' => $person_groups[$key]->booking_is_reserveleader,
 					'booking_studygroup_role'  => $person_groups[$key]->booking_studygroup_role,		
 					))
 				  ->condition('sid', $person_groups[$key]->sid)
-				  ->execute();	
-					
-  				if ($key == 7)
-				{
-  					booking_studygroups_process_colours();
+				  ->execute();
+
+				//check if there is a readings group colour to update
+				foreach ($reading_groups as $group) {
+					if ($group->sid == $key) {
+						booking_studygroups_process_colours();
+					}
 				}
 			}
 			//found this entry already, so no change needed
-			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id == $value)
-			{
+			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id == $value) {
 				watchdog('booking', "Study Group @group session already set to @session.", 
 					array('@group' => $key, '@session' => $value));				
 			}			
 			//no previously defined value, so add a new entry to the mapping table			
-			else
-			{
+			else {
 				watchdog('booking', "Adding Study Group session id: @id for group @group.", array('@id' => $value, '@group' => $key));
 
 				db_insert('booking_studygroup_mapping')
@@ -585,20 +578,18 @@ function booking_studygroups_edit_form_submit($form, &$form_state) {
 						'booking_node_id' => $nid,
 						'booking_studygroup_id' => $key,
 						'booking_session_id' => $value,
-						//'booking_is_leader' => 'N',
-						//'booking_is_helper' => 'N',	
-						//'booking_is_reserveleader' => 'N',
 						'booking_studygroup_role' => 0,
 				  ))
 				  ->execute();
-				  //@todo fix this - should be dynamic not hard coded
-  				if ($key == 7)
-				{
-  					booking_studygroups_process_colours();
+				//check if there is a readings group colour to update
+				foreach ($reading_groups as $group) {
+					if ($group->sid == $key) {
+						booking_studygroups_process_colours();
+					}
 				}
-			}
-		}
-	}
+			}	//end new value check
+		}		//end valid data check		
+	}			//end checkbox loop
 }