How to change the colour of specific arrows on a flow chart

Question

It appears my flowchart is nonplanar (it contains a subdivided K_3,3...)

How do I colour specific arrows, so I can make it visually clearer what's going on when they inevitably cross? (by 'arrows', I mean the whole arrow as opposed to just the arrow head).

Thanks

(/how can I create a 3D flow chart?)

Answer 1

Simply add the color to the options to \draw or \path, such as

\draw[->,thick,dashed,blue]

or

\path[line,red] (a) -- (b);