diff --git a/src/rules.cpp b/src/rules.cpp
index 192cc425f..dc4accd76 100644
--- a/src/rules.cpp
+++ b/src/rules.cpp
@@ -53,7 +53,7 @@ void initializeColorRules ()
     // Load all the configuration values, filter to only the ones that begin with
     // "color.", then store name/value in gsColor, and name in rules.
     std::vector <std::string> rules;
-    for (auto& v : context.config)
+    for (const auto& v : context.config)
     {
       if (! v.first.compare (0, 6, "color.", 6))
       {
@@ -70,7 +70,7 @@ void initializeColorRules ()
     std::vector <std::string> precedence;
     split (precedence, context.config.get ("rule.precedence.color"), ',');
 
-    for (auto& p : precedence)
+    for (const auto& p : precedence)
     {
       // Add the leading "color." string.
       std::string rule = "color." + p;
@@ -90,13 +90,12 @@ void initializeColorRules ()
 ////////////////////////////////////////////////////////////////////////////////
 static void applyColor (const Color& base, Color& c, bool merge)
 {
-    if (merge)
-      c.blend (base);
-    else
-      c = base;
+  if (merge)
+    c.blend (base);
+  else
+    c = base;
 }
 
-
 ////////////////////////////////////////////////////////////////////////////////
 static void colorizeBlocked (Task& task, const Color& base, Color& c, bool merge)
 {
@@ -154,8 +153,8 @@ static void colorizeProject (Task& task, const std::string& rule, const Color& b
   // Observe the case sensitivity setting.
   bool sensitive = context.config.getBoolean ("search.case.sensitive");
 
-  std::string project = task.get ("project");
-  std::string rule_trunc = rule.substr (14);
+  auto project = task.get ("project");
+  auto rule_trunc = rule.substr (14);
 
   // Match project names leftmost.
   if (rule_trunc.length () <= project.length ())
@@ -181,7 +180,7 @@ static void colorizeTagNone (Task& task, const Color& base, Color& c, bool merge
 static void colorizeKeyword (Task& task, const std::string& rule, const Color& base, Color& c, bool merge)
 {
   // Observe the case sensitivity setting.
-  bool sensitive = context.config.getBoolean ("search.case.sensitive");
+  auto sensitive = context.config.getBoolean ("search.case.sensitive");
 
   // The easiest thing to check is the description, because it is just one
   // attribute.
@@ -192,10 +191,10 @@ static void colorizeKeyword (Task& task, const std::string& rule, const Color& b
   // first match.
   else
   {
-    for (auto& it : task.data)
+    for (const auto& att : task.data)
     {
-      if (! it.first.compare (0, 11, "annotation_", 11) &&
-          find (it.second, rule.substr (14), sensitive) != std::string::npos)
+      if (! att.first.compare (0, 11, "annotation_", 11) &&
+          find (att.second, rule.substr (14), sensitive) != std::string::npos)
       {
         applyColor (base, c, merge);
         return;
@@ -208,7 +207,7 @@ static void colorizeKeyword (Task& task, const std::string& rule, const Color& b
 static void colorizeUDA (Task& task, const std::string& rule, const Color& base, Color& c, bool merge)
 {
   // Is the rule color.uda.name.value or color.uda.name?
-  size_t pos = rule.find (".", 10);
+  auto pos = rule.find (".", 10);
   if (pos == std::string::npos)
   {
     if (task.has (rule.substr (10)))
@@ -216,8 +215,8 @@ static void colorizeUDA (Task& task, const std::string& rule, const Color& base,
   }
   else
   {
-    const std::string uda = rule.substr (10, pos - 10);
-    const std::string val = rule.substr (pos + 1);
+    auto uda = rule.substr (10, pos - 10);
+    auto val = rule.substr (pos + 1);
     if ((val == "none" && ! task.has (uda)) ||
         task.get (uda) == val)
       applyColor (base, c, merge);
@@ -229,7 +228,7 @@ static void colorizeDue (Task& task, const Color& base, Color& c, bool merge)
 {
   if (task.has ("due"))
   {
-    Task::status status = task.getStatus ();
+    auto status = task.getStatus ();
     if (status != Task::completed &&
         status != Task::deleted   &&
         task.getDateState ("due") == Task::dateAfterToday)
@@ -242,8 +241,8 @@ static void colorizeDueToday (Task& task, const Color& base, Color& c, bool merg
 {
   if (task.has ("due"))
   {
-    Task::status status = task.getStatus ();
-    Task::dateState dateState = task.getDateState ("due");
+    auto status = task.getStatus ();
+    auto dateState = task.getDateState ("due");
     if (status != Task::completed &&
         status != Task::deleted   &&
         (dateState == Task::dateLaterToday || dateState == Task::dateEarlierToday))
@@ -256,7 +255,7 @@ static void colorizeOverdue (Task& task, const Color& base, Color& c, bool merge
 {
   if (task.has ("due"))
   {
-    Task::status status = task.getStatus ();
+    auto status = task.getStatus ();
     if (status != Task::completed &&
         status != Task::deleted   &&
         task.getDateState ("due") == Task::dateBeforeToday)
@@ -296,7 +295,7 @@ void autoColorize (Task& task, Color& c)
     return;
   }
 
-  bool merge = context.config.getBoolean ("rule.color.merge");
+  auto merge = context.config.getBoolean ("rule.color.merge");
 
   // Note: c already contains colors specifically assigned via command.
   // Note: These rules form a hierarchy - the last rule is King, hence the