Button states keep unchanged across slides when question is submitted.

Dear all,

I'm just newcomer and I am working in a small assignment for my students but I do not know how to work with states. And I would be much appreciated if you could assist me through the work.

In my attachment as you can see, all I want it to be is:

- When I first enter the test , I want the 1 to change colour from orange to blue, for example. And if it is not answered or if it is skipped, the colour is not changed (orange) in the next slide. 

- If the question is submitted, the colour of 1 will be changed to black, it is disabled and that colour keeps unchanged in the rest of the slides.

Thank you and hope your soon reply.