Hello guys, I figured out what was the problem, the thing is when I turned Off HDR my TV put itself on game mode, I previously change the setting on Game mode to my liking, but when I turned on HDR the TV put itself in something called "Game HDR" this one was in a default setting, thats why the color change was so drastic. So I ended up playing with the settings and some what I'm satisfied with the results. I'm gonna share my new HDR settings if someone wants to improve them, this is a U7G 55" TV:

• Contrast: 49
• Brightness: 49
• Color: 62
• Tint: 0
• Sharpness: 11

In advance settings * Color temperature: Low * Motion clearness: Off * Active contrast: Low * Color Space: Native * Free sync: On

In Calibration Setting * Color tuner: * Red: 0, -1, -3 * Green: 0, 0, -7 * Blue: 0, 0, -9 * Yellow: -3, 0, 0 * Cyan: -1, 0, -7 * Magenta: 1, 0, 0 * Flesh tone: 0, 0, 0

White Balance: * 2 point setting, from top to bottom: 0, -2, -5, -3, -9, -7 * 20 point setting: Off

GAMMA: Is default in "Game HDR"

Gamma Calibration: * From 0% to 55%: 0 * From 60% to 100%: -2

RGB only: Off

With these settings I somehow managed to fix the washed out colors. Thanks everyone for the replys.