There is not much more painful to the eyes than turning on a bright display in a dark room. There are applications out there with Night Mode, but they don’t always work optimally—often eliminating colors, which makes things more difficult to read. This is a problem that the Samsung Epic 4G Touch no longer need experience.
XDA Senior Member arpruss has developed an application called GalacticNight. It requires root because it modifies the mdnie* files to adjust the colors for proper night vision. Arpruss explains the application more in depth:
I know there is ChainFire3D, which is a great app, but this is better for nightmode. ChainFire3D does nightmode by simply dropping the green and blue colors. That way of doing things can make some things invisible (e.g., some things in the UI may be pure green, and then they’ll turn black). GalacticNight, instead, properly converts RGB colors to luminosities, and then sets the red (or green or white) intensity according to the luminosity.
There are also a variety of settings based on how you want your phone to look or behave. For instance, the reverse colors mode will change everything around, so white browser backgrounds become black. Additionally, the screen remains mostly dark, which saves battery life on AMOLED devices. The initial version of the application was only compatible for Epic Touch Gingerbread, but since has been found to be working on a number of other devices.
For additional information and the up-to-date list on device compatibility, check out the original thread.
[Thanks to the_scotsman for the assistance!]_________