For a description of the Clamp colors utility, see Clamp.
To clamp colors using the Clamp utility
The Min and Max attribute values determine the amount of Red, Green, or Blue color that appears.
In the following example, the Clamp node is connected to the Marble texture's Vein Color. Because the R and B Min and Max values are set to higher than those of G, the Marble texture's veins appear more red and blue.