Colour group by conservation doesn't work in applet

In the applet, if you create a group, choose a colour scheme, then choose By Conservation...nothing happens.

Reason: CheckboxMenuItem has addItemListener(this) (correctly), but the code to action it is in actionPerformed() - should be in itemStateChanged().
Compare abovePIDColour which is actioned correctly in itemStateChanged().

Seems to have been broken since at least 2.8, comparing code.