diff --git a/toonz/sources/image/tzl/tiio_tzl.cpp b/toonz/sources/image/tzl/tiio_tzl.cpp
index 47c6929..bcdf7f6 100644
--- a/toonz/sources/image/tzl/tiio_tzl.cpp
+++ b/toonz/sources/image/tzl/tiio_tzl.cpp
@@ -40,7 +40,7 @@ char *reverse(char *buffer, int size) {
   }
   return buffer;
 }
-}
+}  // namespace
 
 static int tfwrite(const char *data, const unsigned int count, FILE *f) {
   return fwrite(data, sizeof(char), count, f);
@@ -208,8 +208,8 @@ bool readHeaderAndOffsets(FILE *chan, TzlOffsetMap &frameOffsTable,
       if (version >= 12) fread(&length, sizeof(TINT32), 1, chan);
 
 #if !TNZ_LITTLE_ENDIAN
-      number                    = swapTINT32(number);
-      offs                      = swapTINT32(offs);
+      number = swapTINT32(number);
+      offs   = swapTINT32(offs);
       if (version == 12) length = swapTINT32(length);
 #endif
       //		std::cout << "#" << i << std::hex << " n 0x" << number
@@ -270,16 +270,16 @@ bool readHeaderAndOffsets(FILE *chan, TzlOffsetMap &frameOffsTable,
         level->setFrame(TFrameId(i), TImageP());
   }
 
-  res.lx                                        = lx;
-  res.ly                                        = ly;
-  if (_offsetTablePos) *_offsetTablePos         = offsetTablePos;
+  res.lx = lx;
+  res.ly = ly;
+  if (_offsetTablePos) *_offsetTablePos = offsetTablePos;
   if (_iconOffsetTablePos) *_iconOffsetTablePos = iconOffsetTablePos;
 
   if (_frameCount) *_frameCount = frameCount;
 
   return true;
 }
-}
+}  // namespace
 
 static bool adjustIconAspectRatio(TDimension &outDimension,
                                   TDimension inDimension, TDimension imageRes) {
@@ -295,7 +295,7 @@ static bool adjustIconAspectRatio(TDimension &outDimension,
       double(ly) / inDimension.ly)
     iconLx = tround((double(lx) * inDimension.ly) / ly);
   else
-    iconLy     = tround((double(ly) * inDimension.lx) / lx);
+    iconLy = tround((double(ly) * inDimension.lx) / lx);
   outDimension = TDimension(iconLx, iconLy);
   return true;
 }
@@ -1084,7 +1084,7 @@ void TLevelWriterTzl::renumberFids(
   frameOffsTableTemp        = m_frameOffsTable;
   TzlOffsetMap::iterator it = frameOffsTableTemp.begin();
   while (it != frameOffsTableTemp.end()) {
-    TFrameId fid = it->first;
+    TFrameId fid                                     = it->first;
     std::map<TFrameId, TFrameId>::const_iterator it2 = renumberTable.find(fid);
     if (it2 == renumberTable.end()) remove(fid);
     it++;
@@ -1403,12 +1403,11 @@ bool TLevelWriterTzl::optimize() {
 
 void TLevelReaderTzl::readPalette() {
   TFilePath pltfp = m_path.withNoFrame().withType("tpl");
-  TFileStatus fs(pltfp);
-  TPersist *p = 0;
+  TPersist *p     = 0;
   TIStream is(pltfp);
   TPalette *palette = 0;
 
-  if (is && fs.doesExist()) {
+  if (is) {
     std::string tagName;
     if (is.matchTag(tagName) && tagName == "palette") {
       std::string gname;
diff --git a/toonz/sources/include/toonzqt/icongenerator.h b/toonz/sources/include/toonzqt/icongenerator.h
index 8c366e3..1ca7aa3 100644
--- a/toonz/sources/include/toonzqt/icongenerator.h
+++ b/toonz/sources/include/toonzqt/icongenerator.h
@@ -140,6 +140,10 @@ public:
                                          const TDimension &iconSize,
                                          const TFrameId &fid);
 
+  // This function is called when only colors of styles are changed in toonz
+  // raster levels. In such case it doesn't need to re-compute icons but needs
+  // to let panels to update. See TApp::onLevelColorStyleChanged() for details.
+  void notifyIconGenerated() { emit iconGenerated(); }
 signals:
 
   void iconGenerated();
diff --git a/toonz/sources/toonz/tapp.cpp b/toonz/sources/toonz/tapp.cpp
index d03b861..f5b0bde 100644
--- a/toonz/sources/toonz/tapp.cpp
+++ b/toonz/sources/toonz/tapp.cpp
@@ -631,10 +631,23 @@ void TApp::onLevelColorStyleSwitched() {
 
 static void notifyPaletteChanged(TXshSimpleLevel *simpleLevel) {
   simpleLevel->onPaletteChanged();
+  // palette change can update icons only for ToonzVector / ToonzRaster types
+  if (simpleLevel->getType() != TZP_XSHLEVEL &&
+      simpleLevel->getType() != PLI_XSHLEVEL)
+    return;
   std::vector<TFrameId> fids;
   simpleLevel->getFids(fids);
-  for (int i = 0; i < (int)fids.size(); i++)
-    IconGenerator::instance()->invalidate(simpleLevel, fids[i]);
+  // ToonzRaster level does not need to re-generate icons along with palette
+  // changes since the icons are cached as color mapped images and the current
+  // palette is applied just before using it. So here we just emit the signal to
+  // update related panels.
+  if (simpleLevel->getType() == TZP_XSHLEVEL)
+    IconGenerator::instance()->notifyIconGenerated();
+  else {  // ToonzVecor needs to re-generate icons since it includes colors in
+          // the cache.
+    for (int i = 0; i < (int)fids.size(); i++)
+      IconGenerator::instance()->invalidate(simpleLevel, fids[i]);
+  }
 }
 
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonzlib/imagebuilders.cpp b/toonz/sources/toonzlib/imagebuilders.cpp
index 3e25b73..57b972e 100644
--- a/toonz/sources/toonzlib/imagebuilders.cpp
+++ b/toonz/sources/toonzlib/imagebuilders.cpp
@@ -100,7 +100,10 @@ TImageP ImageLoader::build(int imFlags, void *extData) {
         (m_path.getType() == "psd"))
       lr->loadInfo();
 
-    lr->doReadPalette(true);  // Allow palette loading
+    bool isTlvIcon = data->m_icon && m_path.getType() == "tlv";
+
+    // for TLV icons, palettes will be applied in IconGenerator later
+    if (!isTlvIcon) lr->doReadPalette(true);  // Allow palette loading
 
     TImageReaderP ir = lr->getFrameReader(m_fid);
 
@@ -110,7 +113,7 @@ TImageP ImageLoader::build(int imFlags, void *extData) {
     // Load the image
     TImageP img;
 
-    if (data->m_icon && m_path.getType() == "tlv")
+    if (isTlvIcon)
       img = ir->loadIcon();  // TODO: Why just in the tlv case??
     else {
       ir->setShrink(subsampling);