What can you call me?

I'm not water but I'm not dirt.

I'm stuck somewhere in the middle.

I'm not a liquid nor am I a solid

Just something out of the norm.

And I'm the yellow light.

I'm not as strict as the red

But I'm not as free as the green.

I can't say if you should go or not

But you accept me all the same.

And I'm the peanut butter jelly in your sandwich.

I'm squished in the middle, stuck together.

I can't be one without the other.

Because I am mud.

I am the phenomenon you can't explain.

I'm the thing that takes two to complete.

I'm can't be one without the other.