Request: "instant" change in screen color

[keybounce]

I want the change in screen color to be "instant".

Right now: If I use the keyboard to adjust the color in the preferences, even though the mouse moves immediately to the new number, the screen shifts "slowly". Well, rapidly, but with lots of rapid little changes.

That drives the CPU usage up.

Just the normal change at sunset also takes about a minute, and has lots of little changes -- again, raising the CPU usage.

The issue? It's hot enough to drive up my fan speed, which is noisy. Very. Noisy.

If it makes a difference: this is a 2-GPU laptop.