MAM - Mycelia
Mycelia is located throughout the maps in many forms, it can appear as plant specimens in caves that can be collected by hand or harvested with a chainsaw.
Color Guide - Custom
Using the Customiser allows you select from custom color swatches to change the color of objects in Satisfactory.
Below is a library of colors chosen to match in-game colors like Water, Oil, Plastic etc.
See footer for notes on color.