adjust color
diff --git a/src/cert-tree-model.cpp b/src/cert-tree-model.cpp
index 6af6e4e..3c7362b 100644
--- a/src/cert-tree-model.cpp
+++ b/src/cert-tree-model.cpp
@@ -47,7 +47,7 @@
     {
       QBrush brush(Qt::white, Qt::SolidPattern);
       if (index.row() % 2 == 0) {
-        brush.setColor(Qt::lightGray);
+        brush.setColor(QColor::fromRgb(225, 225, 225));
       }
       return brush;
     }