Acer XB240H monitor, when enetering games changes the blacks to look faded and more grey

[xixWILLxix]

Hey guys I just got my new 144hz monitor with G-sync and once I got all settings up and changed to 144hz the screen flickered a few times and when it come back on the shades of black looked a lot lighter more of a grey than a black I read around about playing with the colour vibrancy in the NVidia control panel and it worked the black became a nice bold black again, but than I went into a game and was fixing settings to go with the 144hz and when it was applying the screen flickered a few times like normal when changing settings but than the blacks became lighter again, it seems it resets every time I change a refresh rate or resolution setting. how can I stop this?

My setup, I7-4770K,GTX770 4gb, MSI Z87-G45, 16gb Gskill RAM, 500gb SSD,1TB HDD, Corsair H100I Cooling.

Thanks in advance

 

[xixWILLxix]

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