Simplify colors

[Jopp-gh]

I love this project so I don't wanna add anything. Just improve one single aspect My request is :

Please only one color for a branch and its child -branches

We get automatically more colors the more main branches we have.

Rainbows colored child branches distract us from understanding the patent - child relationships, so we need to look twice what elements belong to each other.

[lancosch]

Couldn't agree more. If you use a single colour for all branches that would also be better than the current rainbow-coloured version, it is simply distracting.

[pathexplorer]

Interesting, the original source Markmap.js.org could set a single color schema, but in plug-in this option not available