This has probably been mentioned already, but just in case, a lot of dual-damage weapon types seem to have trouble showing the proper color coding for "Weak," "Normal" and "Strong."
Example:
My Blackhawk and later Sentenza is Piercing/Shadow, which means it's supposed to be
Weak against Undead and Robotic.
Normal against Jelly and Fiend
Strong against Beast and Gremlin
Instead it will often show Weak against Jelly and Fiend, and Normal for Beast and Gremlin.
UNTIL that is, I reach Tier 3, where somehow magically the numbers fix themselves and are nice and big and orange against Beasts and Gremlins. Sometimes.
Note that this doesn't affect the actual damage: the numbers themselves are being displayed properly (as far as I can tell). They're just showing up in the wrong color/font.
I've mentioned it in a thread here before, don't feel like looking for it. Something else that strikes me as strange is when using my Acheron on T1 and T2 Gremlins, the first and second swings will show up as normal damage while the third will show up as critical.