gns3-gui/resources/styles/charcoal.css

QWidget {
    color: black;
    background-color: #535353;
}

QToolBar {
    border:0px;
}

QGraphicsView, QTextEdit, QPlainTextEdit, QTreeWidget, QListWidget, QLineEdit, QSpinBox, QComboBox {
  color: black;
  background-color: #dedede;
}

QLabel, QMenu, QStatusBar {
  color: #dedede;
}

QToolBox::tab {
    color: #dedede;
    font: bold 12px;
}

QMenuBar::item {
    background-color: #535353;
}

QMenu::item:selected {
    color: white;
    background-color: #5f5f5f;
}

QToolButton:hover {
    background-color: #5f5f5f;
}

QGroupBox {
    color: #dedede;
    font: bold 12px;
    padding: 15px;
    border-style: none;
}

QAbstractScrollArea::corner {
    background: #535353;
}

QScrollBar::add-page:horizontal, QScrollBar::sub-page:horizontal, QScrollBar::add-page:vertical, QScrollBar::sub-page:vertical {
  background: none
}

QComboBox {
    selection-color: black;
    selection-background-color: #dedede;
}

QComboBox QAbstractItemView {
    color: black;
    background-color: #dedede;
}

QDockWidget, QMenuBar, QPushButton, QToolButton, QTabWidget, QHeaderView::section {
    color: #dedede;
    font: bold 11px;
}

QTabBar {
    color: #dedede;
}

QRadioButton, QCheckBox {
  color: #dedede
}

QRadioButton::disabled, QCheckBox::disabled {
  color: gray;
}