Each default material has its own distinct parameter settings for a variety of properties such as color, reflectivity and surface characteristics such as bump. Adjusting these parameters will tune the look of an existing material to your preference.
To start from a neutral material instead of an existing material, select the Generic material under the Miscellaneous category, add it to your scene and edit it.
If you plan to use precalculated ambient shadows, it is recommended you create and apply them before you adjust your materials to make sure you get the effect you are looking for Apply ambient shadows.
