I am really in love with these at the moment.
I generally use Frixion highlighters or the generic ones that everyone seems to have lying around their office. But I splashed out on these a couple of weeks ago because they are glittery! They also had them in green and purple but I only needed two different colours so I got my two favourites.
Most of my group teaching is done within the Swedish government offices or the parliament (Riksdag). The groups – up to 8 at a time from each body – have the same names (group 1, group 2, group 3 etc) and I have no power to rename the groups. So I colour code all material and bookings for them so that I know which is which. Pink is Riksdag and blue is government offices.