If a user does not have the necessary rights to edit filters, Special:AbuseFilter greys out the Description and Notes fields. The text is #72777d and the background is #eaecf0, resulting in a contrast ratio of 3.817:1 according to this tool. This is below the Web Content Accessibility Guidelines 2.0 AA standard of 4.5:1 for small text meaning that it is hard to read. This is undesirable as all editors should be able to read abuse filter notes and descriptions even if they can not edit them.
Example page: https://en.wikipedia.org/wiki/Special:AbuseFilter/1