Kyatric thanks for the response. Re the Pick all, that was just some experimentation that I should've removed .
When you say put the action 'right after the create action', I think I'm misunderstanding because the following does not work. The 'Log' shows 1 picked object. You made me understand why though, because the created object is not available in the same tick.
[attachment=1:23qhvp04][/attachment:23qhvp04]
I guess you mean this, which does work:
[attachment=0:23qhvp04][/attachment:23qhvp04]
Without the Trigger Once of course this would be done every tick which is not good. However with the Trigger Once I need a way of re-triggering it whenever I spawn a new object that I need to change it's colour. I guess I just need a global 'TriggerColorChange' variable or something which I'd set every time I create a new object, and check for that in the above Every Tick. I suppose that's not so bad.