You shouldn't be pushing your color up from 50 to 65. Nearly every decent set these days does not need any color adjustment. You are simply over saturating the snot out of your colors.
If you don't have a colorimeter, you should only adjust, USING A SET UP DISC, brightness, contrast, sharpness, and backlight (if applicable). If you adjust color, tint, greyscale, or gamma controls you will almost certainly fuck it up.
If you do not know the closest-to-accurate color temp, look up your set on rtings and get it from there.
Re:HDR - this is not a vivid mode color palette swap lol. If you change over to HDR from SDR and see most of the colors have changed, you are doing it wrong. HDR adds dynamic range to your brightness, both in white luminance and color luminance.
Where you will see the difference is typically in spectral highlights, where colors would normally saturate and turn white, they will no longer saturate, instead retain the ability to have color at an luminance not possible in SDR.
There are very few examples where a color SHOULD look different. A firetruck, for instance, should actually appear more red. SDR really could not get 'out' to red. HDR gets closer. Your blues should not look much different.
Additionally, we have no evidence that ANY game has been mastered into a WCG for HDR gaming. Most likely, they have simply been remapped from Rec709 into BT2020. That doesn't mean they cannot still make use of HDR color luminance, just that the base colors all reside within the 709/2020 mapping.
Hope that helps.