In first place say that about QT creator say Qt Creator 2.8.82 (3.0.0-beta), but Create issue don't let me to put this version in Affects Version

I was following the first qt quick tutor from http://qt-project.org/doc/qtcreator-3.0/creator-qml-application.html.

in paragraph "Creating the Main View", when I try to change rectangle color to #343434, the rectangle color don't chage form previous one. I follow the tutor and the same happend when I try to change other colors. If I change view from Design to edit one, I can change color en qml file, and when I back to design the color is ok.