Choices in choice field separated

Hey everyone, here's a question for you: it it possible to separate  the choices in a choice field, let's say with a thin line between them? 

For instance if I have a choice field with these choices: 1, 2, 3, A, B, C, 1., 2., 3. etc,

could I add something between choice "3" and "A" to separate them, and also between choice "C" and "1."?

And one more thing: if choices 1, 2, 3 are set to red and A, B, C set to blue, how can I transfer the colour to a formula that I'm using?

Thanks a lot!! This forum is REALLY VERY HELPFUL!!!