In addition to selecting a rendering path, it’s important to choose a ‘Color Space’ before lighting your project. Color Space determines the maths used by Unity when mixing colors in lighting calculations or reading values from textures. This can have a drastic effect on the realism of your game, but in many cases the decision over which Color Space to use will likely be forced by the hardware limitations of your target platform.
Linear Color Space
The preferred Color Space for realistic rendering is Linear. This can be selected using the ‘Color Space’ property from (Edit>Project Settings>Player).
A significant advantage of using Linear space is that the colors supplied to shaders within your scene will brighten linearly as light intensities increase. With the alternative, ‘Gamma’ Color Space, brightness will quickly begin to turn to white as values go up, which is detrimental to image quality.
Image comparing objects lit using Linear and Gamma Color Space. Notice how colors quickly turn to white as light intensities increase using the Gamma Color Space.
Another main benefit of Linear is that shaders can also sample textures without Gamma (midtone) compensation. This helps to ensure that color values remain consistent throughout their journey through the render pipeline. The result is increased accuracy in color calculations with improved overall realism in the eventual screen output.
Gamma Color Space
Unfortunately Linear Color Space is not supported by some mobile hardware and even certain games consoles. In these instances, Gamma must be used instead. Linear is currently supported on PC, newer mobile hardware and current generation consoles.
It’s important to confirm that your target platform supports your selected Color Space before proceeding.
For more information on Color Space please see the documentation here.