READ AND TRY DEMO FIRST
To get Material Effect as in the pic you need to enable Advanced Lighting Model in :
Preferences > Graphics > Advanced Lighting Model.
6 Colors HUD to change texture to your shorts.
These clothes works only with:
Belleza
Slink
Signature
Legacy
Aesthetic
You may be required to use your mesh bodies alpha HUDs and you may need to change your shape slightly for fitting right for some sizes)
See item in Second LifeDoes not fit Geralt without modifying your legs.
I purchased these as they said they fit Geralt body. They do not autop alpha out spots, and when trying to alpha out the spots peeking through the alpha edges would not line up with the boxer shorts so either have part of open leg alpha out or parts of leg peeking through shorts. Then when doing poses in the pool more parts would peek through. These do not fit Geralt well at all. Just saying. Each person has there own settings but I have never had issues with anything else I purchased for Geralt peeking out or unable to alpha correctly.