We all know rainbow facets don’t work for assassin trap skills.
The damage of traps listed in the skill tooltips includes contributions from + % lightning skill damage and + % fire skill damage. If you equip rainbow facets, the damage in the tooltip updates to include the bonus damage from the facets even though the trap does not do any more damage. The incorrect tooltip is misleading to new players and old players that just plain forgot that + % element damage modifiers don’t apply to traps (which itself isn’t stated anywhere in the game). Anyway, the fix is rather straightforward. Just don’t include it in the calculation for the tooltip and display the correct number.