At the top of every window is the title bar, which displays the name of the application. It also has buttons that are clicked to minimize and restore the window and exit the application (see
Win Minimize windows). When a window is selected, its title bar changes color and becomes the "active" window.
Windows Title Bars
The active window title bars in Win 7 (top) stood out so the user could quickly notice which app was being worked on. In Windows 8, only the X button changed color, and the X in Windows 10 is barely discernible (red arrow). The trend in all software interfaces has been to make the interface sleeker with less regard for functionality.