One of the reasons for this behavior is due to your TV's HDMI port not fully support YCbCr Color Space.
This causes anomalies in the color range negotiation between the TV and the Set-Top-Box resulting in a color overlay on your screen. (Green/Purple/Blue).
This problem is often seen in older TV models.
To solve this you can enable Force RGB Color Space.
This will force the color space negotiation between the TV and the Set-Top-Box to be only RGB.
Go to settings menu > Display
Here, select Force RGB Colorspace and set it to ON.
Note: This problem can also be due to some non-compliant HDCP versions, in this case, you need to check your TV specifications and see if it is HDCP compliant.