And make the gray button locked, it will only unlock if gray was made
Frame one : locked
Frame two: unlocked
{Gray button}
When this is tapped
>{if initial frame equals 2}
>>create Gray cube
Try do this rule example:
{Black Cube}
When this collides with tag #whitecube
>Destroy this actor
>Create Actor Gray cube
>Tell actors with tag #whitecube
>>Destroy this actor
So whenever black and white collide a gray cube appear,