Theoretically, as long as the competition judge doesn't follow the highlighters on Medium, they won't be able to see it. I'm not sure that's 100% true in practice, but I believe the theory eliminates 95%+ of the problem. You may have missed this story, which explains it... https://medium.com/feedium/if-you-dont-like-reading-highlighted-text-there-s-a-solution-8faa5a0cb81c