Replace the term "color space" with "color encoding". Add additional detail to Color class description. State clearly that Color is expected to use the nonlinear sRGB transfer function.

doc/classes/ResourceImporterLayeredTexture.xml

@@ -12,7 +12,7 @@
 	<members>
 		<member name="compress/channel_pack" type="int" setter="" getter="" default="0">
 			Controls how color channels should be used in the imported texture.
-			[b]sRGB Friendly:[/b], prevents the RG color format from being used, as it does not support sRGB color.
+			[b]sRGB Friendly:[/b], prevents the R and RG color formats from being used, as they do not support nonlinear sRGB encoding.
 			[b]Optimized:[/b], allows the RG color format to be used if the texture does not use the blue channel. This reduces memory usage if the texture's blue channel can be discarded (all pixels must have a blue value of [code]0[/code]).
 			[b]Normal Map (RG Channels):[/b] This forces all layers from the texture to be imported with the RG color format, with only the red and green channels preserved. RGTC (Red-Green Texture Compression) compression is able to preserve its detail much better, while using the same amount of memory as a standard RGBA VRAM-compressed texture. This only has an effect on textures with the VRAM Compressed or Basis Universal compression modes. This mode is only available in layered textures ([Cubemap], [CubemapArray], [Texture2DArray] and [Texture3D]).
 		</member>