The Multipliers rollout is part of the Generic material's parameters.
Multipliers
Mode – Specifies how textures and colors will be blended by the multipliers.
Multiply – The texture is blended with a black color.
Blend Amount – The user-specified color is used for blending
Color – Controls the intensity of the Diffuse color.
Reflection Color – Controls the intensity of the reflection color.
Reflection Glossiness* – Controls the intensity of the reflection sharpness.
Refraction Color – Controls the intensity of the refraction color.
IOR* – Controls the intensity of the Index of Refraction value when calculating refraction.
Refraction Glossiness* – Controls the intensity of the refraction sharpness.
Opacity* – Controls the intensity of the overall material Opacity.
Notes
* – When a Bitmap texture is mapped in this slot, its color space is automatically adjusted. Copy-pasting, replacing or wrapping a texture does not trigger this automatic adjustment. It is reserved solely when creating a Bitmap in the specified material slot.