A few years ago I found this egg painter with an easy push button. It's great for kids with poor motor skills because all they have to do is push the button to decorate their egg.
I added food colouring to the egg.
And then we pushed the button to spin it around.
I added another colour and we spun it some more.
For children with very little fine motor control, I used hand-over-hand for spinning.
Here are our beautiful eggs.