Diagnosis
Probably not a bad panel. The factory default settings, particularly the 'Standard' picture mode and low brightness/contrast, are known for being overly conservative and flat.
How to Fix It
Hit the joystick to open the OSD. Go to 'Picture' -> 'Picture Mode'. Switch it to 'sRGB' or 'User' for more accurate, vibrant colors. Then, go into 'Color Setup'. For general use, set 'Color Temp' to 'User' and adjust the RGB gains (try something like R:50, G:48, B:52 to start). Finally, bump up the 'Brightness' and 'Contrast' from their low defaults—try 75 for brightness and 50 for contrast as a starting point.
If That Didn't Work
Check your graphics card settings. Sometimes Windows or your GPU driver (Nvidia Control Panel/AMD Adrenalin) is overriding color settings. Make sure the output dynamic range is set to 'Full' and not 'Limited' for the HDMI/DP connection.
Heads Up
The 'Game' and 'Movie' modes are heavily saturated and not color-accurate. For photo or design work, stick with sRGB or a calibrated User mode.