Use List from the Info menu to find out what sheet your polygon is on, then open your Sheets and Effects dialog and see where that shee is. I have a feeling it might be a newly created one right at the bottom of the list.
Once you know the sheet it's on you can move the sheet above the SYMBOLS sheets in that list and add a few sheet effects to soften it and blend it with the background. I recommend an Edge Fade, Inner effect, followed by either a Transparency effect or a Blend Mode effect set to Multiply and about 15% Opacity.
Answers
Use List from the Info menu to find out what sheet your polygon is on, then open your Sheets and Effects dialog and see where that shee is. I have a feeling it might be a newly created one right at the bottom of the list.
Once you know the sheet it's on you can move the sheet above the SYMBOLS sheets in that list and add a few sheet effects to soften it and blend it with the background. I recommend an Edge Fade, Inner effect, followed by either a Transparency effect or a Blend Mode effect set to Multiply and about 15% Opacity.
Fixed thanks