6500 is the norm/standard colour temp., so it's not 'overwriting', or a custom setting by default.
I'm not 100% sure but I always thought the default setting is to allow the monitor settings to be used.....not AMD graphics. If you want to override what your monitor is set for...then do it manually.
Switching color temperature control in the driver to off is when the work is left to the monitor. But in the new driver you can only deactivate the manual color temperature control when ACTIVATING custom color setting first, and then deselect color temp. So eventhough "Custom color" is turned off, the 6500k manual setting is active. Either that, or all the drivers prior to this handled the auto vs manual color temp incorrectly.
Is this related to your older thread (TV) ?, The right Color Temperature Setting in Driver: Automatic or 6500k?
My older and newer pc monitors have no discernable change, unless I move the slider if I enable it..
And forgot, are you now on 19.12.3 (12.2 was buggy as).
I've put a longer explanation in that other thread.
In short, no, it's not a bug. Color Temperature enabled + temp=6500 is the same behaviour as Custom Color = off, that's why it's default when Custom Color = on.
It is clear that you guys didn't understand the issue here. The "disabled" setting on the left equals the "manual" setting on the right, which is Adrenalin2019. So the color representation I get on manual 6500k with the old driver, I get when setting the new driver to off.
On the other hand, setting Adrenalin2019 to "auto", equals setting the new driver to "ON" and color temp to off.
So again, either the pre Adrenalin 2020 drivers handled the color temp wrong, or the new driver does.
Edit: the prefered setting is to let the monitor handle color temp and leave the driver out of it. Which should be the "auto" or "off" setting