The app highlights lengthy, complex sentences and common errors; if you see a yellow sentence, shorten or split it. If you see a red highlight, your sentence is so dense and complicated that your readers will get lost trying to follow its meandering, convoluted logic—try editing this sentence to remove the red highlight.

You can utilize a simpler word instead of a purple one. Click on highlights to fix them.

Adverbs, passive voice, and other weakening phrases are marked in blue. I believe you should replace them with more forceful language.