When you change the colour of a connecting line to an item, the colour of all subsequent lines change to the same colour. This means that if you realise a line near the beginning of the tree is the wrong colour and change it, you then have to change the colours of at least half the subsequent lines.
I would like to be able to change the colour of a line without it affecting subsequent lines.
This one feature limitation alone causes Mind Maps to not be a stable tool to use. Please prioritize, even if it is just a keyboard shortcut, CTRL + Click or whatever.