Hello there. I'm sorry if this was posted in the wrong place or something. If this is in the wrong area, can someone please move it?

Well anyways. I have little time to get somewhat decent at making pixel art, and I'm having a bit trouble with something at the moment.

I have to make a background that's in a tunnel like place. No matter how much I looked, I never found a good example of how to make one properly.

So basically, I'd really appreciate someone explaining or giving an example on how to shade a tunnel like place that you can only move left and right on.

I'm not sure how to fool the eyes into seeing the background curving like a tunnel. No matter how much I experiment with it I never got it right, so I think it'd be best if I'm properly explained how to do this right. xD

There's a couple of pretty good examples in the Metal Slug games. Check this out and see if you can learn something from it. But yes, it'd probably be best if you'd show us what you've made so we can tell you how to improve it. Make a thread in the WIP forum if you want to do that.