Fixed dropping color on "current color" swatch

* When the color of the "current color" swatch view
   (the bigger one) changes because of a color drop, adopt the
   new color just like when changing the color via other means.

src/apps/icon-o-matic/gui/SwatchGroup.cpp

@@ -85,6 +85,10 @@ SwatchGroup::SwatchGroup(BRect frame)
 	fCurrentColorSV = new SwatchView("current swatch",
 		new BMessage(MSG_COLOR_PICKER), this, color, 28.0, 28.0);
 
+	// When the color of this swatch changes via drag&drop, we want to
+	// adopt it as current color.
+	fCurrentColorSV->SetDroppedMessage(new BMessage(MSG_SET_COLOR));
+
 	// create color field and slider
 	fColorField = new ColorField(BPoint(0.0, 0.0), H_SELECTED,
 		1.0, B_HORIZONTAL);