Black indicates a closed path.
Pink (magenta) indicates an open/unclosed path
Orange indicates the current selection
Orange (dashed) indicates the key object of the current selection.
The other colors are probably stacked overlapping geometry in various states of selection — send us a file and a screen grab and we’ll do our best to work through this with you
Let me start with the disclaimer that color vision is not my strong point!
black: closed path object
pink: open path object
red: rapids in simulation?
brown: ?
orange: selected object
blue: tool path (EDIT: green in simulation)
dashed orange: second selected object (significant in some boolean operations)