sRGB sampling allows the Unity Editor to render ShadersA program that runs on the GPU. More info
See in Glossary in linear color space when Textures are in gamma color space. When you select to work in linear color space, the Editor defaults to using sRGB sampling. If your TexturesAn image used when rendering a GameObject, Sprite, or UI element. Textures are often applied to the surface of a mesh to give it visual detail. More info
See in Glossary are in linear color space, you need to work in linear color space and disable sRGB sampling for each Texture. To learn how to do this, see Disable sRGB sampling for linear textures, below.
Rendering of elements of the Legacy GUI System is always done in gamma space. This means that for the legacy GUI system, Textures with their Texture Type set to Editor GUI and Legacy GUI do not have their gamma removed on import.
It is also important that lookup Textures, masks, and other textures with RGB values that mean something specific and have no gamma correction applied to them bypass sRGB sampling. This prevents values from the sampled Texture having non-existent gamma correction removed before they are used in the Shader, with calculations made with the same value as is stored on disk. Unity assumes that GUI textures and normal mapA type of Bump Map texture that allows you to add surface detail such as bumps, grooves, and scratches to a model which catch the light as if they are represented by real geometry.
See in Glossary textures are authored in a linear space.
For information on how to bypass sRGB sampling, refer to Disable sRGB sampling for linear textures.