U.S. Office Supply Bible Safe Highlighter Set of 6 Bright Flouresent Colors, Dry Bible Highlighters No Bleed, Fade or Smear, Safe Gel Markers, Accessories, Study Guide

There are gel based highlighters specifically for bibles. I have a set and they work very well. These are the ones I have https://www.word.com.au/bible-highlighters-twist-and-glide-set-of-5/highlighter-pack-assorted-colours/6006937122079 if you are in Australia you can buy them in-store or online from Koorong Christian Bookstores, or online from Word Christian Bookstore. Amazon also sell a range for bibles.. https://www.amazon.com.au/U-S-Office-Supply-Bible-Highlighters/dp/B01M0FDEUA?th=1 Other than these, there are neon coloured pencils that would work well https://www.officeworks.com.au/shop/officeworks/p/derwent-academy-neon-coloured-pencils-12-pack-ac2301935