Abs Colour produces absolute values across the red, green and blue channels, effectively making each a positive number by negating the negative values.
This example uses a colour source that produces positive and negative values in the three colour channels. Colour channels may have values greater or lower than the visible range of 0 to 1, hence the black areas in the top preview panel. This pattern is then used as a vector displacement map which in turn displaces a Plane Object to show displacement in three directions.
Abs_Colour_01.jpg
When we insert an Abs Colour node, all negative colours become positive.
Abs_Colour_02.jpg
If there's any errors, omissions or questions about the above, please leave a comment and we will add further details in this post when relevant.
https://planetside.co.uk/wiki/index.php?title=Abs_Colour