| colors | The array of pixel colours to use. This is a 3D texture flattened to a 1D array. | 
| miplevel | The mipmap level to write colorsto. The range is0through the texture's Texture.mipmapCount. The default value is0. | 
Sets the pixel colors of an entire mipmap level.
        This method sets pixel data for the texture in CPU memory. Texture.isReadable must be true, and you must call Apply after SetPixels to upload the changed pixels to the GPU.
Apply is an expensive operation because it copies all the pixels in the texture even if you've only changed some of the pixels, so change as many pixels as possible before you call it.colors must contain the pixels slice by slice starting at the front of the texture. Each slice must contain the pixels row by row, starting at the bottom left of the texture. The size of the array must be the width × height × depth of the mipmap level. 
A single call to SetPixels is usually faster than multiple calls to SetPixel, especially for large textures.SetPixels might be slower than some other texture methods because it converts the Color struct into the format the texture uses. To set pixel data more quickly, use SetPixelData instead.
You can use SetPixels with the following texture formats:
        
          Alpha8
          ARGB32
          ARGB4444
          BGRA32
          R16
          R16_SIGNED
          R8
          R8_SIGNED
          RFloat
          RG16
          RG16_SIGNED
          RG32
          RG32_SIGNED
          RGB24
          RGB24_SIGNED
          RGB48
          RGB48_SIGNED
          RGB565
          RGB9e5Float
          RGBA32
          RGBA32_SIGNED
          RGBA4444
          RGBA64
          RGBA64_SIGNED
          RGBAFloat
          RGBAHalf
          RGFloat
          RGHalf
          RHalf
        
        For all other formats, SetPixels fails. Unity throws an exception when SetPixels fails.
Additional resources: GetPixels, SetPixels32, SetPixelData, Apply, mipmapCount.