By default, the pack restyles the enchanting table's icons and the floating particles around it. The downloaded file also contains an optional add-on that makes those particles colorful. This add-on is a separate pack, so you enable it on its own.
Set up the add-on
1. Open the downloaded file for the pack and find the optional add-on for colorful enchanting table particles.
2. Copy that add-on into your resourcepacks folder. You can open the folder from Options > Resource Packs > Open Pack Folder.
3. Leave the main Ugly Font pack in the folder as well. The add-on works alongside it and does not replace it.
Enable it in the right order
1. Open Options > Resource Packs.
2. Move both the main pack and the colorful particle add-on into the Selected list.
3. Make sure the add-on sits above the main pack. Packs higher in the list override the ones below, so the colorful particles must load on top of the standard ones.
4. Click Done.
Test it
Place an enchanting table in an open spot. Put a few bookshelves near it, because vanilla tables pull floating particles from nearby bookshelves. Watch the particles drift toward the table. They should now appear in color instead of the main pack's default style.
If they still look the same, check that the add-on is above the main pack. Also make sure no other pack in your list changes enchanting particles.