In Wolcen: Lords of Mayhem, you can customize your equipment by adding several colors and choosing a different model for each weapon and weapon type. This tutorial explains everything about customization.
To unlock new models of your equipment, you simply need to collect weapons and weapons by opening chests or removing enemies (image1et2).
As for models, you will always find a dye by eliminating enemies or by opening chests (image3et4). Use these tinctures from your inventory to open them.
Now that you have the models and dye, press the default key "B" to open the cosmetic inventory (image5
Then select the model you want by selecting the model on the left (image7