How can I adjust my screen's color temperature?

Well I know for a fact that there is Cyanogenmod ROM which has "filter options" one of them being only turn on red, I know its not automatic, but there is widgets for the home screen. I'm pretty sure there is a way to do it by app but it would require root access.

https://market.android.com/details?id=com.absurdsoft.neyetlight looks like it would do the trick.

You can try the https://market.android.com/details?id=com.haxor app.

I dont know if this will help but there is an app in the market named "screen adjuster" by NETMAN that allows you to control the red tint on the phone

Twilight works well, although it's just a screen filter, it's automated and very similar to f.lux if you move the color temp to the right more I love it although it does look terrible, it's all we have, and I am not going to root my phone just to have a true color temp change that's insane, plus it voids my warranty which I need to have and rooting is insanely difficult, DO NOT tell me it's easy i've read the instructions for it -- it's NOT EASY

Methods I know of that do change the color of the screen require flashing a custom kernel. I don't know of one that purposely makes the color less accurate, however. One kernel for Galaxy S phones is called http://project-voodoo.org/color. If you're a developer, I suggest contacting them and asking how you could do it; otherwise you'd probably need to hire someone. Edit: Apparently this can be done through an app, I had no idea. Still, this is an option.

It doesn't provide red tint, but for late night, ultra-dim reading I use https://market.android.com/details?id=com.deskangel.adjbrightness. It does require a rooted device.

https://market.android.com/details?id=eu.chainfire.cf3d can do this, but requires ROOT.