I managed to do the swicth of background colors and works fine, but then i added two buttons. I want the buttons to be visible or not, also conditioned by the mouse move. When i go with the mouse over the buttons, the colors of the background start changing over and over.
It's because you're making the buttons appear and disappear.
When you move your mouse over them, your mouse "leaves" the form window and enters the button window, causing your Form2_MouseLeave method to execute, causing your buttons to become invisible. This causes your mouse to "enter" the form window, causing Form2_MouseEnter to execute. This makes your button reappear, causing your mouse to "leave" the form window...An infinite cycle now starts of the button appearing and disappearing.