Highlighting a Specific Proportion of a Data Layer

[SummerlynBingaman]

Hi all!

I am trying to highlight 30% of my data layer. The data layer I am working with is a coral reef vector layer. The purpose of me highlighting a proportion of the reef layer is to show what that 30% looks like for conservation purposes. It's an arbitrary 30% so it doesn't matter how ArcPro highlights it, but if there IS a way to control which direction is highlighted, I'm interested in knowing that too. I have already made a copy of the layer and it has been suggested by some of my co-workers that I manually cut down the vertices on the layer.....but, I am on a deadline and manual editing doesn't seem to be the most efficient solution for me. 

Anything helps, thanks!

[Robert_LeClair]

I wonder if you could incorporated some type of gradient fill for the polygon symbol as seen in the attachment - that would be kind of interesting...

[SummerlynBingaman]

Thank you, Robert! I also have found since then that if I use the field calculator and multiply the area by .30, it creates a new layer showing a random 30% of the area. However, it is a random colorization so I will try the gradient fill to get more of a centralized visual rather than a scattered one. Thanks again!