diff --git a/Plugins/org.blueberry.ui.qt/resources/darkstyle.qss b/Plugins/org.blueberry.ui.qt/resources/darkstyle.qss
index c2ecba2bb3..bda23cf5d0 100644
--- a/Plugins/org.blueberry.ui.qt/resources/darkstyle.qss
+++ b/Plugins/org.blueberry.ui.qt/resources/darkstyle.qss
@@ -1,363 +1,367 @@
 /*===================================================================
 
 BlueBerry Platform
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 /*
   iconColor       = #c7c7c7 <- This line is parsed by MITK
   iconAccentColor = #d4821e <- This line is parsed by MITK
 */
 
 QWidget {
   background-color: #2d2d30;
   border: none;
   color: #f1f1f1;
 }
 
 QWidget:disabled {
   background-color: #2d2d30;
   border-color: #434346;
   color: #656565;
 }
 
 QAbstractButton:hover, QComboBox:hover, QLineEdit:hover {
   background-color: #3f3f46;
 }
 
 QAbstractButton:pressed, QAbstractButton:checked {
   background-color: #434346;
 }
 
 QPushButton {
   border: 1px solid #3f3f46;
   padding: 4px 8px;
 }
 
 QPushButton:pressed {
   border: 1px solid #434346;
 }
 
 QPushButton:checked, QToolButton:checked {
   border: 1px solid #007acc;
 }
 
 QToolButton {
   padding: 2px 2px;
 }
 
+QToolBar QToolButton {
+  padding: 4px 4px;
+}
+
 QAbstractItemView {
   alternate-background-color: #1b1b1c;
   background-color: #252526;
 }
 
 QGroupBox {
   border: 1px solid #434346;
   margin-top: 8px;
   padding-top: 8px;
 }
 
 QGroupBox, QGroupBox:disabled {
   background-color: #252526;
 }
 
 QGroupBox::title {
   padding: 0 4px;
   subcontrol-origin: margin;
   subcontrol-position: top center;
 }
 
 QComboBox, QLineEdit {
   background-color: #333337;
   border: 1px solid #434346;
 }
 
 QComboBox QAbstractItemView {
   border: 1px solid #333337;
   selection-background-color: #3f3f46;
 }
 
 QComboBox::drop-down {
   image: url(":/org.blueberry.ui.qt/dark/down-arrow.svg");
   subcontrol-origin: margin;
   subcontrol-position: right;
   width: 12px;
 }
 
 QComboBox::drop-down:hover {
   background-color: #1f1f20;
   border-left: 1px solid #007acc;
   image: url(":/org.blueberry.ui.qt/dark/down-arrow-pressed.svg");
 }
 
 QCheckBox, QCheckBox:hover, QCheckBox:disabled, QCheckBox:checked, QRadioButton, QRadioButton:hover, QRadioButton:disabled, QRadioButton:checked {
   background-color: none;
 }
 
 QCheckBox::indicator, QRadioButton::indicator {
   height: 13px;
   width: 13px;
 }
 
 QCheckBox::indicator:unchecked {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-unchecked.svg");
 }
 
 QCheckBox::indicator:unchecked:hover {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-unchecked-hover.svg");
 }
 
 QCheckBox::indicator:unchecked:disabled {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-unchecked-disabled.svg");
 }
 
 QCheckBox::indicator:checked {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-checked.svg");
 }
 
 QCheckBox::indicator:checked:hover {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-checked-hover.svg");
 }
 
 QCheckBox::indicator:checked:disabled {
   image: url(":/org.blueberry.ui.qt/dark/checkbox-checked-disabled.svg");
 }
 
 QRadioButton::indicator:unchecked {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-unchecked.svg");
 }
 
 QRadioButton::indicator:unchecked:hover {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-unchecked-hover.svg");
 }
 
 QRadioButton::indicator:unchecked:disabled {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-unchecked-disabled.svg");
 }
 
 QRadioButton::indicator:checked {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-checked.svg");
 }
 
 QRadioButton::indicator:checked:hover {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-checked-hover.svg");
 }
 
 QRadioButton::indicator:checked:disabled {
   image: url(":/org.blueberry.ui.qt/dark/radiobutton-checked-disabled.svg");
 }
 
 QSlider::groove {
   background-color: #686868;
 }
 
 QSlider::groove:hover {
   background-color: #9e9e9e;
 }
 
 QSlider::groove:horizontal {
   height: 3px;
 }
 
 QSlider::groove:vertical {
   width: 3px;
 }
 
 QSlider::handle {
   background-color: #686868;
 }
 
 QSlider::handle:hover {
   background-color: #1c97ea;
 }
 
 QSlider::handle:pressed {
   background-color: #007acc;
 }
 
 QSlider::handle:horizontal {
   margin: -8px 0;
   width: 8px;
 }
 
 QSlider::handle::vertical {
   margin: 0 -8px;
   height: 8px;
 }
 
 QLineEdit:hover {
   border: 1px solid #2b7de1;
 }
 
 QLabel, QLabel:disabled {
   background-color: none;
 }
 
 QMenu {
   border: 1px solid #3e3e40;
 }
 
 QMenu QWidget {
   background-color: #1b1b1c;
 }
 
 QMenu::item {
   background-color: #1b1b1c;
 }
 
 QMenu::item:selected {
   background-color: #333334;
 }
 
 QMenu::separator {
   height: 1px;
   background-color: #3e3e40;
 }
 
 QMenuBar::item:selected {
   background-color: #3e3e40;
 }
 
 QScrollBar {
   background-color: #3e3e42;
 }
 
 QScrollBar:horizontal {
   height: 18px;
   margin: 0 18px 0 18px;
 }
 
 QScrollBar:vertical {
   width: 18px;
   margin: 18px 0 18px 0;
 }
 
 QScrollBar::handle {
   background-color: #686868;
 }
 
 QScrollBar::handle:hover {
     background-color: #9e9e9e;
 }
 
 QScrollBar::handle:pressed {
     background-color: #efebef;
 }
 
 QScrollBar::handle:horizontal {
   min-width: 18px;
   margin: 4px 0 5px 0;
 }
 
 QScrollBar::handle:vertical {
   min-height: 18px;
   margin: 0 5px 0 4px;
 }
 
 QScrollBar::add-page, QScrollBar::sub-page {
   background-color: none;
 }
 
 QScrollBar::add-line, QScrollBar::sub-line {
   background-color: #3e3e42;
   subcontrol-origin: margin;
 }
 
 QScrollBar::add-line:horizontal {
   subcontrol-position: right;
   width: 18px;
 }
 
 QScrollBar::sub-line:horizontal {
   subcontrol-position: left;
   width: 18px;
 }
 
 QScrollBar::add-line:vertical {
   subcontrol-position: bottom;
   height: 18px;
 }
 
 QScrollBar::sub-line:vertical {
   subcontrol-position: top;
   height: 18px;
 }
 
 QScrollBar::up-arrow, QScrollBar::right-arrow, QScrollBar:down-arrow, QScrollBar:left-arrow {
     width: 18px;
     height: 18px;
 }
 
 QScrollBar::down-arrow {
   image: url(":/org.blueberry.ui.qt/dark/down-arrow.svg");
 }
 
 QScrollBar::down-arrow:disabled {
   image: url(":/org.blueberry.ui.qt/dark/down-arrow-disabled.svg");
 }
 
 QScrollBar::down-arrow:hover {
   image: url(":/org.blueberry.ui.qt/dark/down-arrow-hover.svg");
 }
 
 QScrollBar::down-arrow:pressed {
   image: url(":/org.blueberry.ui.qt/dark/down-arrow-pressed.svg");
 }
 
 QScrollBar::left-arrow {
   image: url(":/org.blueberry.ui.qt/dark/left-arrow.svg");
 }
 
 QScrollBar::left-arrow:disabled {
   image: url(":/org.blueberry.ui.qt/dark/left-arrow-disabled.svg");
 }
 
 QScrollBar::left-arrow:hover {
   image: url(":/org.blueberry.ui.qt/dark/left-arrow-hover.svg");
 }
 
 QScrollBar::left-arrow:pressed {
   image: url(":/org.blueberry.ui.qt/dark/left-arrow-pressed.svg");
 }
 
 QScrollBar::right-arrow {
   image: url(":/org.blueberry.ui.qt/dark/right-arrow.svg");
 }
 
 QScrollBar::right-arrow:disabled {
   image: url(":/org.blueberry.ui.qt/dark/right-arrow-disabled.svg");
 }
 
 QScrollBar::right-arrow:hover {
   image: url(":/org.blueberry.ui.qt/dark/right-arrow-hover.svg");
 }
 
 QScrollBar::right-arrow:pressed {
   image: url(":/org.blueberry.ui.qt/dark/right-arrow-pressed.svg");
 }
 
 QScrollBar::up-arrow {
   image: url(":/org.blueberry.ui.qt/dark/up-arrow.svg");
 }
 
 QScrollBar::up-arrow:disabled {
   image: url(":/org.blueberry.ui.qt/dark/up-arrow-disabled.svg");
 }
 
 QScrollBar::up-arrow:hover {
   image: url(":/org.blueberry.ui.qt/dark/up-arrow-hover.svg");
 }
 
 QScrollBar::up-arrow:pressed {
   image: url(":/org.blueberry.ui.qt/dark/up-arrow-pressed.svg");
 }