As of now the contrast/brightness setting of blender under color of a texture are ignored.
Imho this is a very usefull feature in blender, offerign a more versatile use of procedurals. Examples:
- cloud maps are often used for blending, yet the "borders" between light and dark are usually very soft (even in hard noise) - contrast changes that
- procedural maps with a favorable pattern sometimes need to be shifted towards more dark or more light - brightness changes that
- sometimes only nuances are needed, with only a slight difference between darkest to light, eg. in the 50% grey area while keeping the pattern - contrast and brightness are needed here
For now someone needs to generate his own maps out of procedurals and use those as textures, while lackign the feature of an "endless" procedural. As a result: more work with a less favorable result as it stands now.
Using brightness/contrast would be plain cool.
PS: colorband also ;) as of now we cant make decent procedural wood textures :(