[outreachy] Registry: optimize for dark and light mode

[svrnm]

Outreachy task for @SusanGithaigaN

Based on your user experience report, please provide the following suggested improvement via a PR:

Review the registry for elements that need style improvements for either dark/black mode, since they might not be easy to see, visually unappealing or easy to miss.

Note: This is an assigned issue for a participant that has completed the user experience report, if you are an outreachy participant as well, find instructions here: #5290