Rainbow Enchantment Colors (works with 1.19.3 and 1.19.4)
it will say it's for a newer version of Minecraft when loading it onto 1.19.3 but it should work for any version of Minecraft 1.16.5 and above. I only have tested it on 1.19.4 but the file for the old enchantment texture is still in the pack so it should work for older versions because the new enchantment textures don't share the same name as the old enchantment Png file.

Feel free to use this as a base for making your own enchantment glint.