Item Borders config:
# If the hotbar should display item borders.
hotbar = true
# If item borders should show for common items.
show_for_common = false
# If the borders should have square corners.
square_corners = true
# If the borders should fully envelop item slots (otherwise they will only show on the bottom portion of the slot).
full_border = true
# If the borders draw over items instead of under.
over_items = false
# If the borders should have a more prominent glow.
extra_glow = false
# If automatic borders (based on item rarity) should be enabled.
auto_borders = true
# If enabled and Legendary Tooltips is installed, borders will sync with tooltip border colors.
legendary_tooltips_sync = true

Highlighter config:
# If new item markers should be cleared when the inventory is closed.
clear_on_close = true
# If new item markers should be cleared when the item tooltip is displayed.
clear_on_hover = false
# If icons should match the color of items names (as shown in tooltips). Otherwise icons will all be gold.
item_name_color = true
# If new item markers should show on the hotbar.
show_on_hotbar = true

It seems that the items getting the Item name colour.
Fabric 1.19.4 / Loader 0.14.19
Iceberg 1.1.9
Prism 1.0.4
Item Borders 1.2.0
Highlighter 1.1.5

Thank you for the report! I've fixed this issue in version 1.1.6.