I created a ball part and gave it a chequerboard appearance.
I inserted it into an assembly (Ball.png below) and ensured that there was no overiding display state appearance.
When I switch to the Motion Study view, the ball is coloured a default blue/gray (BallMS.png below).
I open the appearance property manager and LC on "Remove appearance". The ball is now the correct color.
I switch to the Model view and check that the ball is the correct color.
I switch to the Motion Study view and the blue/gray color is back.
How can I make the correct color stick?